Objective: To investigate the expression of prostate specific membrane antigen(PSMA) gene and protein in prostate cancer. Method:Expression of PSMA gene and protein were assayed by semiquantitive RT-PCR and immunohistochemistry method in 52 cases of prostate cancer and 35 cases of benign prostatic hyperplasia tissues. Result:①The positive rates of PSMA gene in the tissues of prostate cancer and benign prostatic hyperplasia were 84.6% and 68.6% respectively. Althought there was no significant difference between the two groups, the semiquantitive results showed that the expression level of PSMA gene in prostate cancer was significantly higher than in benign prostatic hyperplasia tissues. ②The positive expression rate of PSMA protein was significantly higher in prostate cancer tissue(94.2%) than that of in benign prostatic hyperplasia tissues(65.7%). Conclusion:The expression levels of PSMA gene and protein were higher in prostate cancer tissues than those of benign prostatic hyperplasia tissues, suggesting that PSMA may be a potential marker for prostate cancer.