diff --git a/module/story/tao.php b/module/story/tao.php
index f86902972c..da77917165 100644
--- a/module/story/tao.php
+++ b/module/story/tao.php
@@ -2106,7 +2106,7 @@ class storyTao extends storyModel
                 if(!empty($story->twins)) $title = $this->lang->story->subDivideTip['twinsSplit'];
                 if(!empty($taskGroups[$story->id])) $title = sprintf($this->lang->story->subDivideTip['notWait'], $this->lang->story->hasDividedTask);
                 if(!empty($caseGroups[$story->id])) $title = sprintf($this->lang->story->subDivideTip['notWait'], $this->lang->story->hasDividedCase);
-                if($story->grade >= $maxGradeGroup[$story->type]) $title = $this->lang->story->errorMaxGradeSubdivide;
+                if(isset($maxGradeGroup[$story->type]) && $story->grade >= $maxGradeGroup[$story->type]) $title = $this->lang->story->errorMaxGradeSubdivide;
                 if($story->status != 'active' && $story->status != 'changing') $title = $this->lang->story->subDivideTip['notActive'];
                 $actions[] = array('name' => 'batchCreate', 'hint' => $title, 'disabled' => true, 'icon' => 'split');
             }