Objective:To evaluate diagnositic value of prostate specific antigen (PSA),free/total PSA (F/T PSA),and PSA density (PSAD) in prostate biopsy. Methods:Total serum PSA and free PSA were detected while F/T PSA value and PSAD were calculated in 285 patients who underwent transrectal ultrasonography-guided prosate biopsy. Optimum PSA,F/T PSA value and PSAD for detecting Pca were discussed. Results:When the cut off value of PSA was set as>15 ng/ml,the diagnostic sensitivity,specificity and the positive predictive value were 70.0%,68.5% and 58.6% respectively. When PSA <15 ng/ml,the difference of PSA between BPA and Pca groups was not significant(t=0.018,P > 0.05),while F/T value and PSAD showed significant differences(t=4.137,3.158,P < 0.01). When the cue off value of F/T was set as 0.16 and the cue off value of PSAD as 0.35 ng/(ml·cm3),the sensitivity,specificity and the positive predictive values were higher. Conclusion:PCa should be highly suspected when PSA is more than 15 ng/ml. The detection rate of prostate cancer could be significantly improved in combination of F/T and/or PSAD.