A method for physical layer random access in a wideband time division duplex mobile communication system in which there is an UpPTS uplink access timeslot for random access, comprising: a) receiving a system broadcast message of a cell, and obtaining frequency band configuration information on the UpPTS timeslot of the cell in the frequency domain; b) selecting a frequency sub-band from frequency sub-bands into which the UpPTS timeslot is divided over the entire used bandwidth according to the obtained frequency band configuration information on the UpPTS timeslot in the frequency domain, and transmitting a random access sequence to a base station in the UpPTS timeslot over the selected frequency sub-band; and c) retransmitting the random access sequence if no response message from the base station is received within a predetermined period; and if a response message is received within the predetermined period, determining whether the received response message from the base station is an affirmative response message or not; determining, by the terminal, a success of the current physical layer random access and proceeding with a subsequent process if the received response message is an affirmative response message; and determining, by the terminal, a failure of the current physical layer random access and proceeding with a corresponding subsequent process if the received response message is a negative response message; characterized in that, the UpPTS timeslot is divided unequally into the bandwidths of the respective frequency sub-bands and the frequency sub-band for transmitting the random access sequence to the base station in the UpPTS timeslot is selected in accordance with a measurement result of signal-to-noise ratios or reception powers of a downlink pilot channel; the frequency band configuration information on the UpPTS timeslot in the frequency domain comprises information on the number of the frequency sub-bands into which the UpPTS timeslot is divided over the entire used bandwidth, information on bandwidths of the respective frequency sub-bands, and information on frequency point locations of the respective frequency sub-bands. a) receiving a system broadcast message of a cell, and obtaining frequency band configuration information on the UpPTS timeslot of the cell in the frequency domain; b) selecting a frequency sub-band from frequency sub-bands into which the UpPTS timeslot is divided over the entire used bandwidth according to the obtained frequency band configuration information on the UpPTS timeslot in the frequency domain, and transmitting a random access sequence to a base station in the UpPTS timeslot over the selected frequency sub-band; and c) retransmitting the random access sequence if no response message from the base station is received within a predetermined period; and if a response message is received within the predetermined period, determining whether the received response message from the base station is an affirmative response message or not; determining, by the terminal, a success of the current physical layer random access and proceeding with a subsequent process if the received response message is an affirmative response message; and determining, by the terminal, a failure of the current physical layer random access and proceeding with a corresponding subsequent process if the received response message is a negative response message;