diff --git a/src/timeline.js b/src/timeline.js
index aeba327..34e3d08 100644
--- a/src/timeline.js
+++ b/src/timeline.js
@@ -1,5 +1,6 @@
 'use strict';
 
+//默认间隔时间
 var DEFAULT_INTERVAL = 1000 / 60;
 
 //初始化状态
@@ -124,4 +125,4 @@ var cancelAnimationFrame = (function () {
 		};
 })();
 
-module.exports = Timeline;
\ No newline at end of file
+module.exports = Timeline;