a demodulation reference signal port mapping method is disclosed . the method includes : a base station communicates with a user equipment , and allocates corresponding data stream to the ue according to the attribution of the ue ; the base station maps the corresponding data stream from a layer to a corresponding demodulation reference signal port ; the base station transmits the corresponding data stream to the ue via demodulation reference signal port . by restricting the demodulation reference signal port mapping solution of rank = 1 to rank = 8 and the demodulation reference signal port mapping solution when the retransmission occurs , the technical solution enables the demodulation reference signal port mapping solution to be compatible with the present system and to keep lower overhead of the demodulation reference signal .