diff --git a/lib/index.js b/lib/index.js
index 8d2deb0..15db6a4 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -3,14 +3,44 @@
   class Delegator {
     constructor (selector/* root选择器 */) {
       // TODO
+      this.root = document.querySelector(selector);
+      this.delegatorEventList = {};
+      this.delegator = e => {        
+        let currentNode = e.target;
+        const targetEventList = this.delegatorEventList[e.type];
+        while (currentNode !== e.currentTarget) {
+          targetEventList.forEach(target => {
+            if (currentNode.matches(target.matcher)) {
+              target.callback.call(currentNode, e);
+            }
+          })
+          currentNode = currentNode.parentNode;
+        }
+      }
     }
 
     on (event/* 绑定事件 */, selector/* 触发事件节点对应选择器 */, fn/* 出发函数 */) {
       // TODO
+      if (!this.delegatorEventList[event]) {
+        this.delegatorEventList[event] = [{
+          matcher: selector,
+          callback: fn
+        }]
+        this.root.addEventListener(event, this.delegator);
+      } else {
+        this.delegatorEventList[event].push({
+          matcher: selector,
+          callback: fn
+        })
+      }
+      return this;
     }
 
     destroy () {
       // TODO
+      Object.keys(this.delegatorEventList).map(eventName => {
+        this.root.removeEventListener(eventName, this.delegator)
+      });
     }
   }