diff --git a/code/reference/ch_socket/SMTPClient.py b/code/reference/ch_socket/SMTPClient.py
new file mode 100644
index 0000000..bfec76a
--- /dev/null
+++ b/code/reference/ch_socket/SMTPClient.py
@@ -0,0 +1,66 @@
+from socket import *
+from base64 import *
+
+mailfrom = "mail from:2@test.com\r\n"
+rcptto = "rcpt to:1@test.com\r\n"
+data = "data\r\n"
+quitmsg = "quit\r\n"
+
+msg = "\r\n I love computer networks!"
+endmsg = "\r\n.\r\n"
+#此处使用易邮邮件服务器软件搭建了一个内网邮件服务器
+mailserver = '10.130.82.62'
+mailport = 25
+connectaddress = (mailserver, mailport)
+# Create socket called clientSocket and establish a TCP connection with mailserver
+clientSocket = socket(AF_INET, SOCK_STREAM)
+clientSocket.connect(connectaddress)
+
+recv = clientSocket.recv(1024)
+print (recv)
+if recv[:3] != '220':
+    print ('220 reply not received from server.')
+# Send HELO command and print server response.
+heloCommand = 'HELO Alice\r\n'
+clientSocket.send(bytes(heloCommand.encode()))
+recv1 = clientSocket.recv(1024)
+print (recv1.decode())
+if recv1[:3] != '250':
+    print ('250 reply not received from server.')
+
+#print('000000000000000')
+#从命令和打印服务器响应发送邮件。
+login = b'auth login\r\n'
+clientSocket.send(login)
+recv2 = clientSocket.recv(1024).decode('utf-8')
+print ('222+',recv2)
+
+userCommand = b64encode('2@test.com'.encode('utf-8'))
+clientSocket.send((str(userCommand,encoding='utf-8')+'\r\n').encode())
+recv3 = clientSocket.recv(1024).decode('utf-8')
+print ('333+',recv3)
+
+password = b64encode('2'.encode('utf-8'))
+clientSocket.send((str(password,encoding='utf-8')+'\r\n').encode())
+recv4 = clientSocket.recv(1024).decode('utf-8')
+print ('444+',recv4)
+
+#print('0000000000000000')
+
+clientSocket.send(bytes(mailfrom.encode()))
+check = clientSocket.recv(1024)
+print(check)
+clientSocket.send(bytes(rcptto.encode()))#将RCPT发送到命令和打印服务器响应。
+check1 = clientSocket.recv(1024)
+print(check1)
+clientSocket.send(bytes(data.encode()))#发送数据命令和打印服务器响应。
+check2 = clientSocket.recv(1024)
+print(check2)
+clientSocket.send(bytes((mailfrom+msg+endmsg).encode()))#发送消息数据。
+check3 = clientSocket.recv(1024)
+print(check3)
+#发送退出命令并获得服务器响应。
+clientSocket.send(bytes(quitmsg.encode()))
+check4 = clientSocket.recv(1024)
+print(check4)
+clientSocket.close()
diff --git a/code/reference/ch_socket/UDP_Pinger_Client.py b/code/reference/ch_socket/UDP_Pinger_Client.py
new file mode 100644
index 0000000..db005cf
--- /dev/null
+++ b/code/reference/ch_socket/UDP_Pinger_Client.py
@@ -0,0 +1,19 @@
+from socket import *
+import time
+serverName = 'localhost'
+serverPort = 12000
+clientSocket = socket(AF_INET, SOCK_DGRAM)
+clientSocket.settimeout(1)
+
+for i in range(0, 10):
+	sendTime = time.time()
+	message = ('Ping %d %s' % (i + 1, sendTime)).encode()
+	try:
+		clientSocket.sendto(message, (serverName, serverPort))
+		modifiedMessage, serverAddress = clientSocket.recvfrom(2048)
+		rtt = time.time() - sendTime
+		print('Sequence %d: Reply from %s  RTT = %.3fs' % (i + 1, serverName, rtt))
+	except Exception as e:
+		print('Sequence %d: Request timed out' % (i + 1))
+
+clientSocket.close()
diff --git a/code/reference/ch_socket/UDP_Pinger_Server.py b/code/reference/ch_socket/UDP_Pinger_Server.py
new file mode 100644
index 0000000..25bda49
--- /dev/null
+++ b/code/reference/ch_socket/UDP_Pinger_Server.py
@@ -0,0 +1,11 @@
+import random
+from socket import *
+serverSocket = socket(AF_INET, SOCK_DGRAM)
+serverSocket.bind(('', 12000))
+while True:
+	rand = random.randint(0, 10)
+	message, address = serverSocket.recvfrom(1024)
+	message = message.upper()
+	if (rand < 4):
+		continue
+	serverSocket.sendto(message, address)
diff --git a/code/reference/ch_socket/Websever.py b/code/reference/ch_socket/Websever.py
new file mode 100644
index 0000000..d901408
--- /dev/null
+++ b/code/reference/ch_socket/Websever.py
@@ -0,0 +1,62 @@
+# Import socket module
+from socket import * 
+import sys # In order to terminate the program
+
+# Create a TCP server socket
+#(AF_INET is used for IPv4 protocols)
+#(SOCK_STREAM is used for TCP)
+
+serverSocket = socket(AF_INET, SOCK_STREAM)
+
+# Assign a port number
+serverPort = 80
+
+# Bind the socket to server address and server port
+serverSocket.bind(("", serverPort))
+
+# Listen to at most 1 connection at a time
+serverSocket.listen(1)
+
+# Server should be up and running and listening to the incoming connections
+
+while True:
+	print('The server is ready to receive')
+
+	# Set up a new connection from the client
+	connectionSocket, addr = serverSocket.accept()
+
+	# If an exception occurs during the execution of try clause
+	# the rest of the clause is skipped
+	# If the exception type matches the word after except
+	# the except clause is executed
+	try:
+		# Receives the request message from the client
+		message = connectionSocket.recv(1024).decode()
+		# Extract the path of the requested object from the message
+		# The path is the second part of HTTP header, identified by [1]
+		filename = message.split()[1]
+		# Because the extracted path of the HTTP request includes 
+		# a character '\', we read the path from the second character 
+		f = open(filename[1:])
+		# Store the entire contenet of the requested file in a temporary buffer
+		outputdata = f.read()
+		# Send the HTTP response header line to the connection socket
+		connectionSocket.send("HTTP/1.1 200 OK\r\n\r\n".encode()) 
+ 
+		# Send the content of the requested file to the connection socket
+		for i in range(0, len(outputdata)):  
+			connectionSocket.send(outputdata[i].encode())
+		connectionSocket.send("\r\n".encode()) 
+		
+		# Close the client connection socket
+		connectionSocket.close()
+
+	except IOError:
+			# Send HTTP response message for file not found
+			connectionSocket.send("HTTP/1.1 404 Not Found\r\n\r\n".encode())
+			connectionSocket.send("<html><head></head><body><h1>404 Not Found</h1></body></html>\r\n".encode())
+			# Close the client connection socket
+			connectionSocket.close()
+
+serverSocket.close()  
+sys.exit()#Terminate the program after sending the corresponding data
diff --git a/code/reference/ch_socket/readme.md b/code/reference/ch_socket/readme.md
new file mode 100644
index 0000000..addcd4e
--- /dev/null
+++ b/code/reference/ch_socket/readme.md
@@ -0,0 +1,12 @@
+# 套接字编程参考实现
+
+# 说明
+
+这个目录中的四个Python文件是实验单元“基于套接字的网络编程”
+中三个实验的参考实现代码。
+
+其中：
+
+* UDP_Pinger_*.py 是实验“套接字基础与UDP通信”的参考实现
+* Websever.py 是实验“TCP通信与Web服务器”的参考实现
+* SMTPClient.py 是实验“SMTP客户端实现”的参考实现
\ No newline at end of file