A terminal registration method uses a session initiation protocol, and more specifically a terminal registration method uses a session initiation protocol for increasing system efficiency and minimizing user mistakes by enabling a terminal to perform registration after receiving an IP address and a telephone number from an Internet access device with the use of an MAC address. In addition, in a VoIP (Voice over Internet Protocol) system including a terminal and a session initiation protocol server, a terminal registration method using a session initiation protocol includes obtaining terminal information by transmitting an MAC address to the session initiation protocol server by the terminal, obtaining user registration information by transmitting the obtained terminal information to the session initiation protocol server by the terminal, and registering in the session initiation protocol server by using the obtained user registration information.