diff --git a/lib/charts/tree.js b/lib/charts/tree.js
index e0ccd51..652a106 100644
--- a/lib/charts/tree.js
+++ b/lib/charts/tree.js
@@ -1,4 +1,7 @@
 /*global EventProxy, d3, Raphael, $ */
+/*!
+ * Tree的兼容性定义
+ */
 ;(function (name, definition) {
     if (typeof define === 'function') {
         define(definition);
@@ -9,6 +12,18 @@
     var DataV = require('DataV');
     var theme = DataV.Themes;
 
+    /**
+     * Tree的构造函数
+     * Examples:
+     * ```
+     * var tree = new Tree("container");
+     * tree.setSource(source);
+     * tree.render();
+     * ```
+     * Options:
+     * - `width`: 画布的宽度
+     * - `height`: 画布的高度
+     */
     var Tree = DataV.extend(DataV.Chart, {
         initialize: function (node, options) {
             this.type = "Tree";
@@ -31,6 +46,25 @@
         }
     });
 
+    /**
+     * 饼图纬度描述
+     */
+    Tree.dimension = {};
+    /**
+     * ID标签
+     */
+    Tree.dimension.id = {
+        type: "string",
+        required: true
+    };
+    /**
+     * 父ID标签
+     */
+    Tree.dimension.pid = {
+        type: "string",
+        required: true
+    };
+
     Tree.prototype.hierarchyTableToJson = function (table) {
         if (table[0][0] === "ID") {
             table = table.slice(1);
@@ -39,6 +73,14 @@
         var rootID;
         var hierarchy = {};
         var addlink = {}; //for multi-fathernode
+        // var ids = _.pluck(table, 0);
+        // var pids = _.pluck(table, 3);
+        // var roots = _.difference(pids, ids);
+        // if (roots.length === 0) {
+        //     throw new Error("root node is empty");
+        // } else if (roots.length > 1) {
+        //     throw new Error("root nodes are too many");
+        // }
 
         table.forEach(function (d, i) {
             if (d[0] === "") {
@@ -74,13 +116,13 @@
         table.forEach(function (d, i) {
             if (d[3]) {
                 var record;
-                var ids = d[3].split('.');
+                var ids = d[3].split(',');
                 if (ids.length === 1) {
                     record = hierarchy[d[3]];
                     record.child.push(d[0]);
                 } else {
                     record = hierarchy[ids[0]];
-                     record.child.push(d[0]);
+                    record.child.push(d[0]);
                     addlink[d[0]] = {child: [], path: [], pnode: []};
 
                     var j, length;