Objective To explore the significance of complexed prostate-specific antigen,total prostate-specific antigen and its ratio in the distinguish diagnosis of prostate cancer and benign prostate hyperplasia.Methods Totally 100 patients,including 30 cases of prostate cancer,40 cases of benign prostate hyperplasia and 30 normal controls were determined the complexed prostate-specific antigen and total prostate-specific antigen with automated chemiluminescence system Bayer ACS: 180 SE.Results Total prostate-specific antigen and complexed prostate-specific antigen in prostate cancer were higher than those in benign prostate hyperplasia and controls.And there was a statistic significance(P0.05).The ratio of complexed to total prostate-specific antigen in prostate cancer was higher than that in benign prostate hyperplasia(P0.05).Conclusion The determination of complexed prostate-specific antigen in prostate cancer has a significance.And the combination of its ratio could effectively distinguish prostate cancer from benign prostate hyperplasia.