Objective To explore the appliacation value of FPSAR between the serum f-PSA and t-PSA in hyperplasia of prostate by YAG Laser.Methods 150 cases with benign prostate hyperplasia(BPH)and 24 cases with prostate pcaancer were selected.The value of f-PSA、t-PSA、FPSAR was determined by TRFIA.Results The tPSA,f-PSA after treatment were significantly lower than before treatment in the two groups(t =2.984,2.701,P ＜0.05).The FPSAR after treatment was significantly higher than before treatment in the two groups(t =2.335,P ＜0.05);The patients of FPSAR≤0.05 in the overlapped field(t-PSA 4～45.5μg/L),the sensitivity of diagnosing PCa is 91.7％(22/24)[t-PSA ＞ 45.5 μg/L(17/24)+(t-PSA 4～45.5 μg/L,FPSAR ≤ 0.15)(5/24)].To examine the PCa with high sensitiveity,it provided the reliable basis for selecting BPH correctly.The patients of BPH group after TUEP was followed up for 6～12 months.The t-PSA is(2.13 ± 0.45)μg/L、f-PSA is(0.85 ± 0.26)μg/L、FPSAR is (0.39 ± 0.06)μg/L.There is no significant difference compared with that after treatment for a month.The international prostate symptom score,(I-PSS)is from(28.3 ± 5.8)points dropped to(12.5 ± 2.1)points.The quality of life,(QOL)is from(4.1 ± 0.6)points dropped to(1.3 ± 0.1)points.The residual urine volume(RUV)is form(93 ±61)ml reduced to(15 ±9)ml.The urination after operation have improvedsignificantly.The Qmax is from average 6.3(2.6～9.5)ml/s before operation raise to 18.4(14.6～22.3)ml/s after operation.Campared with the pre-operation,there is significant difference.Conclusion The application of serum PSA was impoetantin case selection hyperplasia of prostate,comparison of the level changing before and after operation and following up the patients after operation by YAG Laser.