diff --git a/src/pages/01_branch-management/MainPage.vue b/src/pages/01_branch-management/MainPage.vue
index 2370a4ca..df584464 100644
--- a/src/pages/01_branch-management/MainPage.vue
+++ b/src/pages/01_branch-management/MainPage.vue
@@ -157,14 +157,21 @@ const { locale } = useI18n();
 const { data: branchData } = storeToRefs(branchStore);
 
 const treeData = computed(() => {
-  const arr: BranchWithChildren[] = [];
+  const map: Record<string, BranchWithChildren> = {};
+  const children: Branch[] = [];
 
-  branchData.value?.result.forEach((a) => {
-    if (a.isHeadOffice) arr.push(Object.assign(a, { branch: [] }));
-    else arr.find((b) => b.id === a.headOfficeId)?.branch.push(a);
+  branchData.value?.result.forEach((v) => {
+    if (v.isHeadOffice) map[v.id] = Object.assign(v, { branch: [] });
+    else children.push(v);
   });
 
-  return arr;
+  children.forEach((v) => {
+    if (v.headOfficeId && map[v.headOfficeId]) {
+      map[v.headOfficeId].branch.push(v);
+    }
+  });
+
+  return Object.values(map);
 });
 
 async function calculateStats() {