diff --git a/packages/toast-ui.grid/src/dispatch/rowSpan.ts b/packages/toast-ui.grid/src/dispatch/rowSpan.ts
index e3f910389..58b4c941d 100644
--- a/packages/toast-ui.grid/src/dispatch/rowSpan.ts
+++ b/packages/toast-ui.grid/src/dispatch/rowSpan.ts
@@ -23,7 +23,10 @@ export function updateRowSpanWhenAppending(data: Row[], prevRow: Row, extendPrev
       const startOffset = keyRow || extendPrevRowSpan ? 1 : -count + 1;
 
       // keep rowSpan state when appends row in the middle of rowSpan
-      if (mainRowSpan.spanCount > startOffset) {
+      if (
+        mainRowSpan.spanCount > startOffset ||
+        (mainRowSpan.spanCount === 1 && startOffset === 1)
+      ) {
         mainRowSpan.count += 1;
         mainRowSpan.spanCount += 1;
 
diff --git a/packages/toast-ui.grid/src/store/data.ts b/packages/toast-ui.grid/src/store/data.ts
index c8d5b85ef..bccff5bad 100644
--- a/packages/toast-ui.grid/src/store/data.ts
+++ b/packages/toast-ui.grid/src/store/data.ts
@@ -354,7 +354,8 @@ function createSubRowSpan(prevRowSpanMap: RowSpanMap) {
   Object.keys(prevRowSpanMap).forEach((columnName) => {
     const prevRowSpan = prevRowSpanMap[columnName];
     const { mainRowKey, count, spanCount } = prevRowSpan;
-    if (spanCount > 1 - count) {
+
+    if (spanCount > 1 && spanCount > 1 - count) {
       const subRowCount = count >= 0 ? -1 : count - 1;
       subRowSpanMap[columnName] = createRowSpan(false, mainRowKey, subRowCount, spanCount);
     }