目的　探讨总前列腺特异抗原 (T PSA)、游离PSA (F PSA)与T PSA比例 (F/T PSA)、前列腺特异性抗原密度(PSAD)在前列腺癌鉴别诊断中的价值。方法　检测 6 4例良性前列腺增生 (BPH)和 2 1例前列腺癌 (PCA)病人血清的T PSA、F PSA和前列腺体积 ,对F/T PSA、PSAD进行统计比较和ROC分析。结果　BPH组和PCA组病人的T PSA、F/T PSA、PSAD存在显著性差异 (P <0 0 5 ) ,在ROC曲线中 ,PSAD的AUC =0 89,F/T PSA的AUC =0 6 3。结论　PSAD比F/T PSA对前列腺癌鉴别诊断更有价值 Objective To investigate the value of total prostate specific antigen (T PSA), free PSA (F PSA) to T PSA ratio (F / T PSA) and prostate specific antigen density (PSAD) in the differential diagnosis of prostate cancer. Methods The serum T PSA, F PSA and prostate volume of 64 benign prostatic hyperplasia (BPH) and 21 prostate cancer (PCA) patients were detected. The statistical analysis and ROC analysis of F / T PSA and PSAD were performed. Results There were significant differences in T PSA, F / T PSA and PSAD between BPH group and PCA group (P <0 05). In the ROC curve, AUC of PSAD was 0 89 and AUC of F / T PSA was 0 6 3. Conclusion PSAD is more valuable than F / T PSA in the differential diagnosis of prostate cancer