Objective To investigate the influence of HLA immunogenic mismatching (IM) on acute rejection of renal transplants.Methods The function recovery time of renal allograft and the rate of acute rejection of 196 cases after cadaveric renal transplantation wereanalyzed. Results IM of HLA locus did not influence the function recovery time of the renal allograft. The IM of HLA-A locus did not increase the rate of allograft acute rejection whereas the HLA-B locus did and the HLA-DR increased the acute rejection rate significantly. Conclusion IM should not be ignored in HLA typing. HLA-B locus is related to the allograft acute rejection, while the IM of DR locus increasesthe allograft acute rejection rate significantly.