A terminal random access method for a cellular radio communications system and a method for generating a group identifier are provided. In the terminal random access method for a cellular radio communications system, random access preamble message is transmitted by a terminal to a base station in a random access time slot in a radio frame; location information of the random access time slot in the radio frame and that in the frequency domain are combined to generate a group identifier and sending a random access response message to the terminal after adding the group identifier and an individual identifier that corresponds to the random access preamble message to the random access response message by the base station; it is judged whether the random access response message that corresponds to the sent random access preamble message is received, by judging whether the group identifier and the individual identifier within the received random access response message are all expected values.