diff --git a/frontend/src/app/admin/cars/page.tsx b/frontend/src/app/admin/cars/page.tsx
index ea5a9a6..a0be49f 100644
--- a/frontend/src/app/admin/cars/page.tsx
+++ b/frontend/src/app/admin/cars/page.tsx
@@ -2703,10 +2703,13 @@ export default function CarsAdminPage() {
                       <div className="flex items-center gap-2">
                         <input
                           type="number"
-                          value={(selectedCar.margin_krw || 0) / 10000}
-                          onChange={(e) => {
+                          defaultValue={(selectedCar.margin_krw || 0) / 10000}
+                          key={`margin_krw_${selectedCar.id}_${selectedCar.margin_krw}`}
+                          onBlur={(e) => {
                             const marginValue = parseInt(e.target.value || '0') * 10000;
-                            handleUpdateCar(selectedCar.id, { margin_krw: marginValue });
+                            if (marginValue !== (selectedCar.margin_krw || 0)) {
+                              handleUpdateCar(selectedCar.id, { margin_krw: marginValue });
+                            }
                           }}
                           className="w-24 px-2 py-1 border border-gray-300 rounded text-right"
                           min="0"
@@ -2720,10 +2723,13 @@ export default function CarsAdminPage() {
                       <div className="flex items-center gap-2">
                         <input
                           type="number"
-                          value={(selectedCar.margin_mn || 0) / 10000}
-                          onChange={(e) => {
+                          defaultValue={(selectedCar.margin_mn || 0) / 10000}
+                          key={`margin_mn_${selectedCar.id}_${selectedCar.margin_mn}`}
+                          onBlur={(e) => {
                             const marginValue = parseInt(e.target.value || '0') * 10000;
-                            handleUpdateCar(selectedCar.id, { margin_mn: marginValue });
+                            if (marginValue !== (selectedCar.margin_mn || 0)) {
+                              handleUpdateCar(selectedCar.id, { margin_mn: marginValue });
+                            }
                           }}
                           className="w-24 px-2 py-1 border border-gray-300 rounded text-right"
                           min="0"