diff --git a/Observable.js b/Observable.js
index 03545cd..3546645 100644
--- a/Observable.js
+++ b/Observable.js
@@ -11,12 +11,19 @@ class ObserverList {
   }
   add(observer) {
     // todo add observer to list
+    this.observerList.push(observer)
   }
   remove(observer) {
     // todo remove observer from list
+    const matchIndex = this.observerList.findIndex(observer => observer === observer)
+
+    if (matchIndex > -1) {
+      this.observerList.splice(matchIndex, 1)
+    }
   }
   count() {
     // return observer list size
+    return this.observerList.length
   }
 }
 
@@ -26,12 +33,17 @@ class Subject {
   }
   addObserver(observer) {
     // todo add observer
+    this.observers.add(observer)
   }
   removeObserver(observer) {
     // todo remove observer
+    this.observers.remove(observer)
   }
   notify(...args) {
     // todo notify
+    this.observers.observerList.forEach(observer => {
+      observer.update(...args)
+    });
   }
 }
 
diff --git a/PubSub.js b/PubSub.js
index 0c7999e..49d3928 100644
--- a/PubSub.js
+++ b/PubSub.js
@@ -12,15 +12,41 @@ module.exports = class PubSub {
   }
 
   subscribe(type, fn) {
-    // todo subscribe
+    if (!type || !fn) return;
+    if (!this.subscribers[type]) {
+      this.subscribers[type] = []
+    }
+
+    this.subscribers[type].push(fn)
   }
 
   unsubscribe(type, fn) {
-    // todo unsubscribe
+    if(!type) return
+    const subscribeFns = this.subscribers[type]
+
+    if (!subscribeFns || subscribeFns.length === 0) return
+    
+    if(!fn) this.subscribers[type] = []
+    
+    for (let i = 0, len = subscribeFns.length; i < len; i++) {
+      if (subscribeFns[i] === fn) {
+        subscribeFns.splice(i, 1)
+        return
+      }
+    }
+    
   }
 
   publish(type, ...args) {
-    // todo publish
+    if (!type) return
+    const subscribeFns = this.subscribers[type]
+    if (!subscribeFns || subscribeFns.length === 0) return
+    
+    if (subscribeFns.length === 1) return subscribeFns[0](...args)
+    
+    for (let i = 0, len = subscribeFns.length; i < len; i++) {
+      subscribeFns[i](...args)
+    }
   }
 
 }