diff --git a/src/Editor/SelectBox.ts b/src/Editor/SelectBox.ts
index a2b7da32c..d1bdd582e 100644
--- a/src/Editor/SelectBox.ts
+++ b/src/Editor/SelectBox.ts
@@ -7,6 +7,7 @@ import { SelectSetBase, SelectType } from './SelectSet';
 
 /**
  * 矩形选区
+ * 如果图形无法选择,那么注意该图形是否调用计算图形的包围球.
  * 
  * @export
  * @class SelectBox