diff --git a/packages/ketcher-core/src/application/editor/operations/monomer/monomerFactory.ts b/packages/ketcher-core/src/application/editor/operations/monomer/monomerFactory.ts
index b286bf8efc..f283cad059 100644
--- a/packages/ketcher-core/src/application/editor/operations/monomer/monomerFactory.ts
+++ b/packages/ketcher-core/src/application/editor/operations/monomer/monomerFactory.ts
@@ -5,13 +5,17 @@ import {
   RNABaseRenderer,
   SugarRenderer,
   PhosphateRenderer,
+  UnresolvedMonomerRenderer,
 } from 'application/render/renderers';
 import { MonomerItemType } from 'domain/types';
-import { Peptide } from 'domain/entities/Peptide';
-import { Chem } from 'domain/entities/Chem';
-import { Sugar } from 'domain/entities/Sugar';
-import { Phosphate } from 'domain/entities/Phosphate';
-import { RNABase } from 'domain/entities/RNABase';
+import {
+  Peptide,
+  Chem,
+  Sugar,
+  Phosphate,
+  RNABase,
+  UnresolvedMonomer,
+} from 'domain/entities';
 import { KetMonomerClass } from 'application/formatters/types/ket';
 
 type DerivedClass<T> = new (...args: unknown[]) => T;
@@ -47,7 +51,11 @@ export const monomerFactory = (
   let MonomerRenderer;
   let ketMonomerClass: KetMonomerClass;
 
-  if (
+  if (monomer.props.unresolved) {
+    Monomer = UnresolvedMonomer;
+    MonomerRenderer = UnresolvedMonomerRenderer;
+    ketMonomerClass = KetMonomerClass.CHEM;
+  } else if (
     monomer.props.MonomerType === MONOMER_CONST.CHEM ||
     (monomer.props.MonomerType === MONOMER_CONST.RNA &&
       (monomer.props.MonomerClass === MONOMER_CONST.MODDNA ||
diff --git a/packages/ketcher-core/src/application/formatters/types/ket.ts b/packages/ketcher-core/src/application/formatters/types/ket.ts
index 6233a67a77..a0cfbbf236 100644
--- a/packages/ketcher-core/src/application/formatters/types/ket.ts
+++ b/packages/ketcher-core/src/application/formatters/types/ket.ts
@@ -122,6 +122,7 @@ export interface IKetMonomerTemplate {
   classHELM?: string;
   name?: string;
   idtAliases?: IKetIdtAliases;
+  unresolved?: boolean;
 }
 
 export interface IKetMonomerTemplateRef {
diff --git a/packages/ketcher-core/src/application/render/renderers/UnresolvedMonomerRenderer.ts b/packages/ketcher-core/src/application/render/renderers/UnresolvedMonomerRenderer.ts
new file mode 100644
index 0000000000..df06a420b4
--- /dev/null
+++ b/packages/ketcher-core/src/application/render/renderers/UnresolvedMonomerRenderer.ts
@@ -0,0 +1,44 @@
+import { BaseMonomerRenderer } from 'application/render/renderers/BaseMonomerRenderer';
+import { UnresolvedMonomer } from 'domain/entities';
+import { Selection } from 'd3';
+
+const UNRESOLVED_MONOMER_SELECTED_ELEMENT_ID = '#unresolved-monomer-selection';
+const UNRESOLVED_MONOMER_HOVERED_ELEMENT_ID = '#unresolved-monomer-hover';
+const UNRESOLVED_MONOMER_SYMBOL_ELEMENT_ID = '#unresolved-monomer';
+
+export class UnresolvedMonomerRenderer extends BaseMonomerRenderer {
+  constructor(public monomer: UnresolvedMonomer, scale?: number) {
+    super(
+      monomer,
+      UNRESOLVED_MONOMER_SELECTED_ELEMENT_ID,
+      UNRESOLVED_MONOMER_HOVERED_ELEMENT_ID,
+      UNRESOLVED_MONOMER_SYMBOL_ELEMENT_ID,
+      scale,
+    );
+  }
+
+  public get textColor() {
+    return 'white';
+  }
+
+  protected appendBody(
+    rootElement: Selection<SVGGElement, void, HTMLElement, never>,
+  ) {
+    return rootElement
+      .append('use')
+      .data([this])
+      .attr('href', UNRESOLVED_MONOMER_SYMBOL_ELEMENT_ID);
+  }
+
+  show(theme) {
+    super.show(theme);
+  }
+
+  protected get enumerationElementPosition() {
+    return undefined;
+  }
+
+  protected get beginningElementPosition() {
+    return undefined;
+  }
+}
diff --git a/packages/ketcher-core/src/application/render/renderers/index.ts b/packages/ketcher-core/src/application/render/renderers/index.ts
index 8ae82188d2..2683b32229 100644
--- a/packages/ketcher-core/src/application/render/renderers/index.ts
+++ b/packages/ketcher-core/src/application/render/renderers/index.ts
@@ -6,4 +6,5 @@ export { RNABaseRenderer } from './RNABaseRenderer';
 export { BaseRenderer } from './BaseRenderer';
 export { BaseMonomerRenderer } from './BaseMonomerRenderer';
 export { PolymerBondRenderer } from './PolymerBondRenderer';
+export { UnresolvedMonomerRenderer } from './UnresolvedMonomerRenderer';
 export * from './sequence';
diff --git a/packages/ketcher-core/src/application/render/renderers/sequence/SequenceNodeRendererFactory.ts b/packages/ketcher-core/src/application/render/renderers/sequence/SequenceNodeRendererFactory.ts
index b0550de404..af2d656df7 100644
--- a/packages/ketcher-core/src/application/render/renderers/sequence/SequenceNodeRendererFactory.ts
+++ b/packages/ketcher-core/src/application/render/renderers/sequence/SequenceNodeRendererFactory.ts
@@ -1,18 +1,27 @@
-import { Chem, Peptide, Phosphate, Vec2 } from 'domain/entities';
-import { PeptideSequenceItemRenderer } from 'application/render/renderers/sequence/PeptideSequenceItemRenderer';
-import { ChemSequenceItemRenderer } from 'application/render/renderers/sequence/ChemSequenceItemRenderer';
-import { PhosphateSequenceItemRenderer } from 'application/render/renderers/sequence/PhosphateSequenceItemRenderer';
-import { NucleotideSequenceItemRenderer } from 'application/render/renderers/sequence/NucleotideSequenceItemRenderer';
+import {
+  Chem,
+  Peptide,
+  Phosphate,
+  Vec2,
+  Nucleotide,
+  Nucleoside,
+  EmptySequenceNode,
+  LinkerSequenceNode,
+  UnresolvedMonomer,
+} from 'domain/entities';
+import {
+  PeptideSequenceItemRenderer,
+  ChemSequenceItemRenderer,
+  PhosphateSequenceItemRenderer,
+  NucleotideSequenceItemRenderer,
+  EmptySequenceItemRenderer,
+  BaseMonomerRenderer,
+  BaseSequenceItemRenderer,
+  NucleosideSequenceItemRenderer,
+  UnresolvedMonomerSequenceItemRenderer,
+} from 'application/render';
 import { SubChainNode } from 'domain/entities/monomer-chains/types';
-import { Nucleotide } from 'domain/entities/Nucleotide';
-import { Nucleoside } from 'domain/entities/Nucleoside';
 import { BaseSubChain } from 'domain/entities/monomer-chains/BaseSubChain';
-import { EmptySequenceNode } from 'domain/entities/EmptySequenceNode';
-import { EmptySequenceItemRenderer } from 'application/render/renderers/sequence/EmptySequenceItemRenderer';
-import { BaseMonomerRenderer } from 'application/render';
-import { BaseSequenceItemRenderer } from 'application/render/renderers/sequence/BaseSequenceItemRenderer';
-import { LinkerSequenceNode } from 'domain/entities/LinkerSequenceNode';
-import { NucleosideSequenceItemRenderer } from './NucleosideSequenceItemRenderer';
 
 export class SequenceNodeRendererFactory {
   static fromNode(
@@ -50,6 +59,9 @@ export class SequenceNodeRendererFactory {
           case Chem:
             RendererClass = ChemSequenceItemRenderer;
             break;
+          case UnresolvedMonomer:
+            RendererClass = UnresolvedMonomerSequenceItemRenderer;
+            break;
           default:
             RendererClass = ChemSequenceItemRenderer;
             break;
diff --git a/packages/ketcher-core/src/application/render/renderers/sequence/UnresolvedMonomerSequenceItemRenderer.ts b/packages/ketcher-core/src/application/render/renderers/sequence/UnresolvedMonomerSequenceItemRenderer.ts
new file mode 100644
index 0000000000..2c408fa139
--- /dev/null
+++ b/packages/ketcher-core/src/application/render/renderers/sequence/UnresolvedMonomerSequenceItemRenderer.ts
@@ -0,0 +1,11 @@
+import { BaseSequenceItemRenderer } from 'application/render/renderers/sequence/BaseSequenceItemRenderer';
+
+export class UnresolvedMonomerSequenceItemRenderer extends BaseSequenceItemRenderer {
+  get symbolToDisplay(): string {
+    return '?';
+  }
+
+  protected drawModification(): void {
+    return undefined;
+  }
+}
diff --git a/packages/ketcher-core/src/application/render/renderers/sequence/index.ts b/packages/ketcher-core/src/application/render/renderers/sequence/index.ts
index 3922aa5b05..fb3304da49 100644
--- a/packages/ketcher-core/src/application/render/renderers/sequence/index.ts
+++ b/packages/ketcher-core/src/application/render/renderers/sequence/index.ts
@@ -1,2 +1,14 @@
 export * from './SequenceRenderer';
 export * from './BaseSequenceItemRenderer';
+export * from './BackBoneBondSequenceRenderer';
+export * from './BaseSequenceRenderer';
+export * from './ChemSequenceItemRenderer';
+export * from './EmptySequenceItemRenderer';
+export * from './NucleotideSequenceItemRenderer';
+export * from './NucleosideSequenceItemRenderer';
+export * from './PeptideSequenceItemRenderer';
+export * from './PhosphateSequenceItemRenderer';
+export * from './PolymerBondSequenceRenderer';
+export * from './RNASequenceItemRenderer';
+export * from './SequenceNodeRendererFactory';
+export * from './UnresolvedMonomerSequenceItemRenderer';
diff --git a/packages/ketcher-core/src/domain/entities/UnresolvedMonomer.ts b/packages/ketcher-core/src/domain/entities/UnresolvedMonomer.ts
new file mode 100644
index 0000000000..40de09becc
--- /dev/null
+++ b/packages/ketcher-core/src/domain/entities/UnresolvedMonomer.ts
@@ -0,0 +1,24 @@
+import { BaseMonomer, Peptide } from 'domain/entities';
+import { ChemSubChain } from 'domain/entities/monomer-chains/ChemSubChain';
+import { PeptideSubChain } from 'domain/entities/monomer-chains/PeptideSubChain';
+import { SubChainNode } from 'domain/entities/monomer-chains/types';
+
+export class UnresolvedMonomer extends BaseMonomer {
+  public getValidSourcePoint(monomer?: BaseMonomer) {
+    return Peptide.prototype.getValidSourcePoint.call(this, monomer);
+  }
+
+  public getValidTargetPoint(monomer: BaseMonomer) {
+    return Peptide.prototype.getValidTargetPoint.call(this, monomer);
+  }
+
+  public get SubChainConstructor() {
+    return ChemSubChain;
+  }
+
+  public isMonomerTypeDifferentForChaining(monomerToChain: SubChainNode) {
+    return ![PeptideSubChain, ChemSubChain].includes(
+      monomerToChain.SubChainConstructor,
+    );
+  }
+}
diff --git a/packages/ketcher-core/src/domain/entities/index.ts b/packages/ketcher-core/src/domain/entities/index.ts
index cc618dc2cf..a9588b0c30 100644
--- a/packages/ketcher-core/src/domain/entities/index.ts
+++ b/packages/ketcher-core/src/domain/entities/index.ts
@@ -48,3 +48,6 @@ export * from './Nucleoside';
 export * from './Nucleotide';
 export * from './monomer-chains/types';
 export * from './MonomerSequenceNode';
+export * from './EmptySequenceNode';
+export * from './LinkerSequenceNode';
+export * from './UnresolvedMonomer';
diff --git a/packages/ketcher-core/src/domain/entities/monomer-chains/Chain.ts b/packages/ketcher-core/src/domain/entities/monomer-chains/Chain.ts
index c63b26b64c..dbc834f6ae 100644
--- a/packages/ketcher-core/src/domain/entities/monomer-chains/Chain.ts
+++ b/packages/ketcher-core/src/domain/entities/monomer-chains/Chain.ts
@@ -5,6 +5,7 @@ import {
   Phosphate,
   SubChainNode,
   Sugar,
+  UnresolvedMonomer,
 } from 'domain/entities';
 import {
   getNextMonomerInChain,
@@ -49,6 +50,11 @@ export class Chain {
   public add(monomer: BaseMonomer) {
     this.createSubChainIfNeed(monomer);
 
+    if (monomer instanceof UnresolvedMonomer) {
+      this.lastSubChain.add(new MonomerSequenceNode(monomer));
+      return;
+    }
+
     if (monomer instanceof Sugar) {
       if (isValidNucleoside(monomer, this.firstMonomer)) {
         this.lastSubChain.add(Nucleoside.fromSugar(monomer, false));
@@ -59,10 +65,12 @@ export class Chain {
         return;
       }
     }
+
     if (monomer instanceof Peptide) {
       this.lastSubChain.add(new MonomerSequenceNode(monomer));
       return;
     }
+
     const nextMonomer = getNextMonomerInChain(monomer);
     const isNextMonomerNucleosideOrNucleotideOrPeptide = () => {
       const isNucleosideOrNucleotide =
diff --git a/packages/ketcher-core/src/domain/entities/monomer-chains/ChainsCollection.ts b/packages/ketcher-core/src/domain/entities/monomer-chains/ChainsCollection.ts
index 91eb166233..de6d7b867c 100644
--- a/packages/ketcher-core/src/domain/entities/monomer-chains/ChainsCollection.ts
+++ b/packages/ketcher-core/src/domain/entities/monomer-chains/ChainsCollection.ts
@@ -7,6 +7,7 @@ import {
   Phosphate,
   RNABase,
   Sugar,
+  UnresolvedMonomer,
 } from 'domain/entities';
 import {
   getNextMonomerInChain,
@@ -102,7 +103,8 @@ export class ChainsCollection {
       | typeof Phosphate
       | typeof Sugar
       | typeof RNABase
-    > = [Peptide, Chem, Phosphate, Sugar, RNABase],
+      | typeof UnresolvedMonomer
+    > = [Peptide, Chem, Phosphate, Sugar, RNABase, UnresolvedMonomer],
   ) {
     const monomersList = monomers.filter((monomer) =>
       MonomerTypes.some((MonomerType) => monomer instanceof MonomerType),
diff --git a/packages/ketcher-core/src/domain/serializers/ket/fromKet/monomerToDrawingEntity.ts b/packages/ketcher-core/src/domain/serializers/ket/fromKet/monomerToDrawingEntity.ts
index ff62788dff..7b566df587 100644
--- a/packages/ketcher-core/src/domain/serializers/ket/fromKet/monomerToDrawingEntity.ts
+++ b/packages/ketcher-core/src/domain/serializers/ket/fromKet/monomerToDrawingEntity.ts
@@ -17,6 +17,7 @@ export function templateToMonomerProps(template: IKetMonomerTemplate) {
     MonomerClass: template.class,
     MonomerCaps: {},
     idtAliases: template.idtAliases,
+    unresolved: template.unresolved,
   };
 }
 
diff --git a/packages/ketcher-core/src/domain/serializers/ket/ketSerializer.ts b/packages/ketcher-core/src/domain/serializers/ket/ketSerializer.ts
index 3b066ad397..54be506a10 100644
--- a/packages/ketcher-core/src/domain/serializers/ket/ketSerializer.ts
+++ b/packages/ketcher-core/src/domain/serializers/ket/ketSerializer.ts
@@ -325,6 +325,10 @@ export class KetSerializer implements Serializer<Struct> {
     template: IKetMonomerTemplate,
     monomerItem: MonomerItemType,
   ) {
+    if (monomerItem.props.unresolved) {
+      return;
+    }
+
     const { attachmentPointsList } =
       BaseMonomer.getAttachmentPointDictFromMonomerDefinition(
         template.attachmentPoints || [],
diff --git a/packages/ketcher-core/src/domain/types/monomers.ts b/packages/ketcher-core/src/domain/types/monomers.ts
index 0802155b20..cc4351f91e 100644
--- a/packages/ketcher-core/src/domain/types/monomers.ts
+++ b/packages/ketcher-core/src/domain/types/monomers.ts
@@ -38,6 +38,7 @@ export type MonomerItemType = {
     MonomerClass?: string;
     isMicromoleculeFragment?: boolean;
     idtAliases?: IKetIdtAliases;
+    unresolved?: boolean;
   };
   attachmentPoints?: IKetAttachmentPoint[];
   seqId?: number;
diff --git a/packages/ketcher-macromolecules/src/Editor.tsx b/packages/ketcher-macromolecules/src/Editor.tsx
index 238d030a6f..6cabc4a9f3 100644
--- a/packages/ketcher-macromolecules/src/Editor.tsx
+++ b/packages/ketcher-macromolecules/src/Editor.tsx
@@ -71,6 +71,7 @@ import {
   SugarAvatar,
   PhosphateAvatar,
   RNABaseAvatar,
+  UnresolvedMonomerAvatar,
 } from 'components/shared/monomerOnCanvas';
 import { MonomerConnectionOnlyProps } from 'components/modal/modalContainer/types';
 import { ErrorModal } from 'components/modal/Error';
@@ -372,6 +373,7 @@ function Editor({ theme, togglerComponent }: EditorProps) {
               <SugarAvatar />
               <PhosphateAvatar />
               <RNABaseAvatar />
+              <UnresolvedMonomerAvatar />
               <SequenceStartArrow />
             </defs>
             <g className="drawn-structures"></g>
diff --git a/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/index.tsx b/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/index.tsx
index 849f65e81d..aa13f20547 100644
--- a/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/index.tsx
+++ b/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/index.tsx
@@ -20,6 +20,7 @@ import { preview } from '../../../constants';
 import styled from '@emotion/styled';
 import { useAppSelector } from 'hooks';
 import { selectShowPreview } from 'state/common';
+import UnresolvedMonomerPreview from 'components/shared/UnresolvedMonomerPreview/UnresolvedMonomerPreview';
 
 const MonomerPreview = ({ className }: IPreviewProps) => {
   const preview = useAppSelector(selectShowPreview);
@@ -39,20 +40,26 @@ const MonomerPreview = ({ className }: IPreviewProps) => {
         data-testid="polymer-library-preview"
       >
         <MonomerName>{preview.monomer.struct.name}</MonomerName>
-        <StyledStructRender
-          struct={preview.monomer.struct}
-          options={{ needCache: false }}
-        />
+        {preview.monomer.props?.unresolved ? (
+          <UnresolvedMonomerPreview />
+        ) : (
+          <StyledStructRender
+            struct={preview.monomer.struct}
+            options={{ needCache: false }}
+          />
+        )}
       </ContainerDynamic>
     )
   );
 };
 
-const StyledPreview = styled(MonomerPreview)`
+const StyledPreview = styled(MonomerPreview)<IPreviewProps>`
   z-index: 5;
   position: absolute;
-  width: ${preview.width}px;
-  height: ${preview.height}px;
+  width: ${(props) =>
+    props.unresolvedMonomer ? 'auto' : preview.width + 'px'};
+  height: ${(props) =>
+    props.unresolvedMonomer ? 'auto' : preview.height + 'px'};
   transform: translate(-50%, 0);
 `;
 
diff --git a/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/types.ts b/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/types.ts
index 83255788e1..a0b13acd69 100644
--- a/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/types.ts
+++ b/packages/ketcher-macromolecules/src/components/shared/MonomerPreview/types.ts
@@ -13,7 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  ***************************************************************************/
-
 export interface IPreviewProps {
   className?: string;
+  unresolvedMonomer?: boolean;
 }
diff --git a/packages/ketcher-macromolecules/src/components/shared/Preview/index.tsx b/packages/ketcher-macromolecules/src/components/shared/Preview/index.tsx
index 1916fb4ee1..8c9474074d 100644
--- a/packages/ketcher-macromolecules/src/components/shared/Preview/index.tsx
+++ b/packages/ketcher-macromolecules/src/components/shared/Preview/index.tsx
@@ -38,5 +38,10 @@ export const Preview = () => {
     return <MonomerWithIDTAliasesPreview className="polymer-library-preview" />;
   }
 
-  return <MonomerPreview className="polymer-library-preview" />;
+  return (
+    <MonomerPreview
+      className="polymer-library-preview"
+      unresolvedMonomer={preview?.monomer?.props?.unresolved}
+    />
+  );
 };
diff --git a/packages/ketcher-macromolecules/src/components/shared/UnresolvedMonomerPreview/UnresolvedMonomerPreview.tsx b/packages/ketcher-macromolecules/src/components/shared/UnresolvedMonomerPreview/UnresolvedMonomerPreview.tsx
new file mode 100644
index 0000000000..28fb89396d
--- /dev/null
+++ b/packages/ketcher-macromolecules/src/components/shared/UnresolvedMonomerPreview/UnresolvedMonomerPreview.tsx
@@ -0,0 +1,13 @@
+import { Icon } from 'ketcher-react';
+import { StyledContent } from 'components/shared/UnresolvedMonomerPreview/styles';
+
+const UnresolvedMonomerPreview = () => {
+  return (
+    <StyledContent>
+      <Icon name="questionMark" />
+      Unknown structure
+    </StyledContent>
+  );
+};
+
+export default UnresolvedMonomerPreview;
diff --git a/packages/ketcher-macromolecules/src/components/shared/UnresolvedMonomerPreview/styles.ts b/packages/ketcher-macromolecules/src/components/shared/UnresolvedMonomerPreview/styles.ts
new file mode 100644
index 0000000000..6dcbaae3da
--- /dev/null
+++ b/packages/ketcher-macromolecules/src/components/shared/UnresolvedMonomerPreview/styles.ts
@@ -0,0 +1,14 @@
+import styled from '@emotion/styled';
+
+export const StyledContent = styled.div`
+  width: 70px;
+  height: 77px;
+  display: flex;
+  flex-direction: column;
+  justify-content: center;
+  align-items: center;
+  gap: 8px;
+  padding: 8px;
+  color: #7c7c7f;
+  border: 1px solid #cad3dd;
+`;
diff --git a/packages/ketcher-macromolecules/src/components/shared/monomerOnCanvas/UnresolvedMonomer.tsx b/packages/ketcher-macromolecules/src/components/shared/monomerOnCanvas/UnresolvedMonomer.tsx
new file mode 100644
index 0000000000..8f3ddc8d83
--- /dev/null
+++ b/packages/ketcher-macromolecules/src/components/shared/monomerOnCanvas/UnresolvedMonomer.tsx
@@ -0,0 +1,66 @@
+/****************************************************************************
+ * Copyright 2021 EPAM Systems
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ***************************************************************************/
+
+export const UnresolvedMonomerAvatar = () => (
+  <>
+    <symbol id="unresolved-monomer" viewBox="0 0 59 59" width="59" height="59">
+      <rect
+        className="monomer-body"
+        width="29.5"
+        height="29.5"
+        data-actual-width="29.5"
+        data-actual-height="29.5"
+        x="0.5"
+        y="0.5"
+        rx="1.5"
+        stroke="#333333"
+      />
+      <rect
+        width="29.5"
+        height="29.5"
+        data-actual-width="29.5"
+        data-actual-height="29.5"
+        x="0.5"
+        y="0.5"
+        rx="1.5"
+        fill="#585858"
+      />
+    </symbol>
+    <symbol id="unresolved-monomer-selection">
+      <rect
+        width="29.5"
+        height="29.5"
+        x="0.5"
+        y="0.5"
+        rx="1.5"
+        fill="none"
+        stroke="#0097A8"
+      />
+    </symbol>
+    <symbol id="unresolved-monomer-hover">
+      <rect
+        width="29.5"
+        height="29.5"
+        x="0.5"
+        y="0.5"
+        rx="1.5"
+        fill="none"
+        stroke="#0097A8"
+        strokeWidth="1.5"
+      />
+    </symbol>
+  </>
+);
diff --git a/packages/ketcher-macromolecules/src/components/shared/monomerOnCanvas/index.ts b/packages/ketcher-macromolecules/src/components/shared/monomerOnCanvas/index.ts
index 669ceaccad..f791e51cb1 100644
--- a/packages/ketcher-macromolecules/src/components/shared/monomerOnCanvas/index.ts
+++ b/packages/ketcher-macromolecules/src/components/shared/monomerOnCanvas/index.ts
@@ -3,3 +3,4 @@ export { PeptideAvatar } from './Peptide';
 export { SugarAvatar } from './Sugar';
 export { PhosphateAvatar } from './Phosphate';
 export { RNABaseAvatar } from './RNABase';
+export { UnresolvedMonomerAvatar } from './UnresolvedMonomer';
diff --git a/packages/ketcher-react/src/assets/icons/files/questionMark.svg b/packages/ketcher-react/src/assets/icons/files/questionMark.svg
new file mode 100644
index 0000000000..5b27f84f49
--- /dev/null
+++ b/packages/ketcher-react/src/assets/icons/files/questionMark.svg
@@ -0,0 +1,3 @@
+<svg width="16" height="26" viewBox="0 0 16 26" fill="none" xmlns="http://www.w3.org/2000/svg">
+    <path opacity="0.5" d="M6.32564 17.7969C5.77336 17.7969 5.32564 17.3492 5.32564 16.7969V16.483C5.34784 15.3997 5.47053 14.867 5.73616 14.0057C6.00983 13.1444 6.39619 12.4522 6.89525 11.929C7.3943 11.3977 8.00202 10.9107 8.7184 10.468C9.2094 10.1622 9.64809 9.82813 10.0345 9.46591C10.4289 9.09564 10.7388 8.68513 10.9641 8.23438C11.1895 7.77557 11.3022 7.26444 11.3022 6.70099C11.3022 6.06511 11.1533 5.51373 10.8555 5.04688C10.5577 4.58002 10.1552 4.2178 9.64809 3.96023C9.14903 3.70265 8.58961 3.57386 7.96982 3.57386C7.39832 3.57386 6.855 3.69863 6.33985 3.94815C5.83275 4.18963 5.41016 4.5599 5.07209 5.05895C4.88976 5.33022 4.75166 5.64203 4.65778 5.99438C4.5209 6.5081 4.10012 6.9304 3.56847 6.9304H1.24506C0.682474 6.9304 0.223374 6.46472 0.299555 5.90731C0.44799 4.82124 0.791203 3.88244 1.32919 3.09091C2.03753 2.06061 2.97124 1.28788 4.13033 0.772727C5.29747 0.257576 6.58535 0 7.99397 0C9.53137 0 10.8836 0.26965 12.0508 0.808949C13.226 1.34825 14.1396 2.11695 14.7916 3.11506C15.4516 4.10511 15.7816 5.2803 15.7816 6.64062C15.7816 7.55824 15.6327 8.37926 15.3349 9.10369C15.0451 9.82812 14.6306 10.4721 14.0913 11.0355C13.552 11.599 12.9121 12.102 12.1715 12.5447C11.5195 12.9472 10.9843 13.3658 10.5657 13.8004C10.1552 14.2351 9.83529 14.5515 9.63406 15.1391C9.49159 15.4657 9.38729 15.9478 9.34624 16.483V16.7969C9.34624 17.3492 8.89852 17.7969 8.34624 17.7969H6.32564ZM7.4265 25.331C6.70206 25.331 6.07825 25.0734 5.55505 24.5582C5.03185 24.0431 4.77025 23.4152 4.77025 22.6747C4.77025 21.9503 5.03185 21.3305 5.55505 20.8153C6.07825 20.3002 6.70206 20.0426 7.4265 20.0426C8.14288 20.0426 8.76267 20.3002 9.28587 20.8153C9.81712 21.3305 10.0827 21.9503 10.0827 22.6747C10.0827 23.1657 9.95798 23.6125 9.70846 24.0149C9.46698 24.4174 9.14501 24.7393 8.74255 24.9808C8.34813 25.2143 7.90945 25.331 7.4265 25.331Z" fill="currentColor"/>
+</svg>
diff --git a/packages/ketcher-react/src/components/Icon/utils/iconNameToIcon.ts b/packages/ketcher-react/src/components/Icon/utils/iconNameToIcon.ts
index f045539876..4341ae24f7 100644
--- a/packages/ketcher-react/src/components/Icon/utils/iconNameToIcon.ts
+++ b/packages/ketcher-react/src/components/Icon/utils/iconNameToIcon.ts
@@ -222,6 +222,7 @@ import ExplicitHydrogensIcon from '../../../assets/icons/files/explicit-hydrogen
 import FlexLayoutIcon from '../../../assets/icons/files/flex-layout-mode.svg';
 import SnakeLayoutIcon from '../../../assets/icons/files/snake-layout-mode.svg';
 import SequenceLayoutIcon from '../../../assets/icons/files/sequence-layout-mode.svg';
+import QuestionMark from '../../../assets/icons/files/questionMark.svg';
 
 export const iconNameToIcon = {
   α,
@@ -444,4 +445,5 @@ export const iconNameToIcon = {
   'flex-layout-mode': FlexLayoutIcon,
   'snake-layout-mode': SnakeLayoutIcon,
   'sequence-layout-mode': SequenceLayoutIcon,
+  questionMark: QuestionMark,
 } as const;