diff --git a/frontend/components/dataflow/DataFlowDesigner.tsx b/frontend/components/dataflow/DataFlowDesigner.tsx
index 6561b65d..406b372b 100644
--- a/frontend/components/dataflow/DataFlowDesigner.tsx
+++ b/frontend/components/dataflow/DataFlowDesigner.tsx
@@ -56,6 +56,7 @@ export const DataFlowDesigner: React.FC<DataFlowDesignerProps> = ({
     pendingConnection,
     setPendingConnection,
     currentDiagramId,
+    setCurrentDiagramId,
     currentDiagramName,
     setCurrentDiagramName,
     currentDiagramCategory,
@@ -93,6 +94,9 @@ export const DataFlowDesigner: React.FC<DataFlowDesignerProps> = ({
     const loadDiagramData = async () => {
       if (diagramId && diagramId > 0) {
         try {
+          // 편집 모드일 때 currentDiagramId 설정
+          setCurrentDiagramId(diagramId);
+
           const jsonDiagram = await DataFlowAPI.getJsonDataFlowDiagramById(diagramId, companyCode);
           if (jsonDiagram) {
             // 관계도 이름 설정
@@ -217,7 +221,16 @@ export const DataFlowDesigner: React.FC<DataFlowDesignerProps> = ({
     };
 
     loadDiagramData();
-  }, [diagramId, companyCode, setCurrentDiagramName, setNodes, setEdges, setTempRelationships, handleColumnClick]);
+  }, [
+    diagramId,
+    companyCode,
+    setCurrentDiagramId,
+    setCurrentDiagramName,
+    setNodes,
+    setEdges,
+    setTempRelationships,
+    handleColumnClick,
+  ]);
 
   // 키보드 이벤트 핸들러 (Del 키로 선택된 노드 삭제)
   useEffect(() => {
@@ -661,17 +674,26 @@ export const DataFlowDesigner: React.FC<DataFlowDesignerProps> = ({
             })) as any, // plan 전체를 any로 캐스팅
         };
 
-        if (diagramId && diagramId > 0) {
-          // 기존 관계도 수정
+        if ((diagramId && diagramId > 0) || (currentDiagramId && currentDiagramId > 0)) {
+          // 기존 관계도 수정 (prop diagramId 또는 내부 currentDiagramId 사용)
+          const targetDiagramId = diagramId || currentDiagramId;
           await DataFlowAPI.updateJsonDataFlowDiagram(
-            diagramId,
+            targetDiagramId!,
             saveRequest,
             companyCode,
             authUser?.userId || "SYSTEM",
           );
         } else {
           // 새로운 관계도 생성
-          await DataFlowAPI.createJsonDataFlowDiagram(saveRequest, companyCode, authUser?.userId || "SYSTEM");
+          const newDiagram = await DataFlowAPI.createJsonDataFlowDiagram(
+            saveRequest,
+            companyCode,
+            authUser?.userId || "SYSTEM",
+          );
+
+          // 새로 생성된 다이어그램 ID를 내부 상태에 저장 (다음 저장부터는 업데이트 모드)
+          setCurrentDiagramId(newDiagram.diagram_id);
+          setCurrentDiagramName(newDiagram.diagram_name);
         }
 
         toast.success(`관계도 "${diagramName}"가 성공적으로 저장되었습니다.`);
@@ -688,11 +710,14 @@ export const DataFlowDesigner: React.FC<DataFlowDesignerProps> = ({
       nodes,
       tempRelationships,
       diagramId,
+      currentDiagramId,
       companyCode,
       authUser?.userId,
       setIsSaving,
       setHasUnsavedChanges,
       setShowSaveModal,
+      setCurrentDiagramId,
+      setCurrentDiagramName,
     ],
   );