diff --git a/src/App.vue b/src/App.vue
index e8d4cc9c..2d76021e 100644
--- a/src/App.vue
+++ b/src/App.vue
@@ -19,14 +19,9 @@ export default defineComponent({
   setup() {
     const store = useStore()
     const screening = computed(() => store.state.screening)
-    window.onbeforeunload = function(e: Event) {
-      e = e || window.event
-      // 兼容IE8和Firefox 4之前的版本
-      if (e) {
-        e.returnValue = false
-      }
-      // Chrome, Safari, Firefox 4+, Opera 12+ , IE 9+
-      return false
+
+    if (process.env.NODE_ENV === 'production') {
+      window.onbeforeunload = () => false
     }
 
     onMounted(() => {
diff --git a/src/views/Editor/Canvas/ElementCreateSelection.vue b/src/views/Editor/Canvas/ElementCreateSelection.vue
index 2dcfc78c..2f9104da 100644
--- a/src/views/Editor/Canvas/ElementCreateSelection.vue
+++ b/src/views/Editor/Canvas/ElementCreateSelection.vue
@@ -38,8 +38,8 @@ export default defineComponent({
     const ctrlOrShiftKeyActive = computed<boolean>(() => store.getters.ctrlOrShiftKeyActive)
     const creatingElement = computed(() => store.state.creatingElement)
 
-    const start = ref<[number, number] | null>(null)
-    const end = ref<[number, number] | null>(null)
+    const start = ref<[number, number]>()
+    const end = ref<[number, number]>()
 
     const selectionRef = ref<HTMLElement>()
     const offset = reactive({
@@ -110,13 +110,25 @@ export default defineComponent({
 
         const minSize = 30
 
-        if (Math.abs(endPageX - startPageX) >= minSize || Math.abs(endPageY - startPageY) >= minSize) {
+        if (Math.abs(endPageX - startPageX) >= minSize && Math.abs(endPageY - startPageY) >= minSize) {
           emit('created', {
             start: start.value,
             end: end.value,
           })
         }
-        else store.commit(MutationTypes.SET_CREATING_ELEMENT, null)
+        else {
+          const defaultSize = 100
+          const minX = Math.min(endPageX, startPageX)
+          const minY = Math.min(endPageY, startPageY)
+          const maxX = Math.max(endPageX, startPageX)
+          const maxY = Math.max(endPageY, startPageY)
+          const offsetX = maxX - minX >= minSize ? maxX - minX : defaultSize
+          const offsetY = maxY - minY >= minSize ? maxY - minY : defaultSize
+          emit('created', {
+            start: [minX, minY],
+            end: [minX + offsetX, minY + offsetY],
+          })
+        }
       }
     }