diff --git a/zh-cn/python3-cn.html.markdown b/zh-cn/python3-cn.html.markdown
index 1f294ebb..4059c876 100644
--- a/zh-cn/python3-cn.html.markdown
+++ b/zh-cn/python3-cn.html.markdown
@@ -123,8 +123,7 @@ False or True #=> True
 # None是一个对象
 None  # => None
 
-# Don't use the equality "==" symbol to compare objects to None
-# Use "is" instead. This checks for equality of object identity.
+# 当与None进行比较时不要用 ==，要用is。is是用来比较两个变量是否指向同一个对象。
 "etc" is None  # => False
 None is None  # => True
 
@@ -482,52 +481,50 @@ filter(lambda x: x > 5, [3, 4, 5, 6, 7])   # => [6, 7]
 ####################################################
 
 
-# We subclass from object to get a class.
+# 定义一个继承object的类
 class Human(object):
 
-    # A class attribute. It is shared by all instances of this class
+    # 类属性，被所有此类的实例共用。
     species = "H. sapiens"
 
-    # Basic initializer, this is called when this class is instantiated.
-    # Note that the double leading and trailing underscores denote objects
-    # or attributes that are used by python but that live in user-controlled
-    # namespaces. You should not invent such names on your own.
+    # 构造方法，当实例被初始化时被调用。注意名字前后的双下划线，这是表明这个属
+    # 性或方法对Python有特殊意义，但是允许用户自行定义。你自己取名时不应该用这
+    # 种格式。
     def __init__(self, name):
         # Assign the argument to the instance's name attribute
         self.name = name
 
-    # An instance method. All methods take "self" as the first argument
+    # 实例方法，第一个参数总是self，就是这个实例对象
     def say(self, msg):
         return "{name}: {message}".format(name=self.name, message=msg)
 
-    # A class method is shared among all instances
-    # They are called with the calling class as the first argument
+    # 类方法，被所有此类的实例共用。第一个参数是这个类对象。
     @classmethod
     def get_species(cls):
         return cls.species
 
-    # A static method is called without a class or instance reference
+    # 静态方法。调用时没有实例或类的绑定。
     @staticmethod
     def grunt():
         return "*grunt*"
 
 
-# Instantiate a class
+# 构造一个实例
 i = Human(name="Ian")
-print(i.say("hi"))     # prints out "Ian: hi"
+print(i.say("hi"))     # 印出 "Ian: hi"
 
 j = Human("Joel")
-print(j.say("hello"))  # prints out "Joel: hello"
+print(j.say("hello"))  # 印出 "Joel: hello"
 
-# Call our class method
+# 调用一个类方法
 i.get_species()   # => "H. sapiens"
 
-# Change the shared attribute
+# 改一个共用的类属性
 Human.species = "H. neanderthalensis"
 i.get_species()   # => "H. neanderthalensis"
 j.get_species()   # => "H. neanderthalensis"
 
-# Call the static method
+# 调用静态方法
 Human.grunt()   # => "*grunt*"