The embodiment of the invention discloses a method for sending a ranging code response message, which comprises the steps of: sending ranging code information, wherein the ranging code information comprises a response position corresponding to a ranging code; receiving the ranging code sent by a terminal according to the ranging code information; and sending a response message at the response position of the ranging code. Simultaneously, the embodiment of the invention also discloses a terminal, a base station and a network system on the basis of the method. After the response position of the ranging code is sent, the response message is sent at the response position of the ranging code, so that the terminal only needs to receive a corresponding message on a frame or subframe determined by the response position without monitoring the response message continuously. Thus, power sources can be economized effectively.