Objective: To test and verify the effects of prostatitis decoction and its capsule on the treatment of chronic prostatitis with blood stasis Syndrome, and its therapeutic mechanism. Methods: The total of 561 patients were treated for 2 months, decoction group 322 cases, and capsule group 239 cases. As control group, 95 patients were treated with Qianliekang (前列康) tablets. Expressed prostatic secretion (EPS) pH and Zn content were measured before and after treatment. Observation on hemorheology and microcirculation disturbance with animal experiments were conducted. Results: The cure rate of prostatitis decoction and capsule groups was 65.8%, and 54.4% respectively, that of the control group was only 17.9%. EPS pH and Zn were markedly improved after prostatitis decoction treatment. Experimental work revealed that prostatitis decoction and its capsule had lowered the whole blood viscosity, thrombocyte adhesiveness rate and dry weight of thrombus in blood stasis rabbit model; and on rats model of microcirculation disturbance caused by adrenalin, the prostatitis decoction and its capsules had obviously delayed the occurrence of reduction and stopping of blood flow in arterioles. Conclusion: Prostatitis decoction (capsule) was effective in treating chronic prostatitis. Objective: To test and verify the effects of prostatitis decoction and its capsule on the treatment of chronic prostatitis with blood stasis Syndrome, and its therapeutic mechanism. Methods: The total of 561 patients were treated for 2 months, decoction group 322 cases, and capsule group 239 cases. As control group, 95 patients were treated with Qianliekang tablets. Expressed prostatic secretion (EPS) pH and Zn content were measured before and after treatment. Observation on hemorheology and microcirculation disturbance with animal experiments were conducted. Results : The cure rate of prostatitis decoction and capsule groups was 65.8%, and 54.4% respectively, that of the control group was only only 17.9%. EPS and Zn were markedly improved after prostatitis decoction treatment. Experimental work showed that prostatitis decoction and its capsule had lowered the whole blood viscosity, thrombocyte adhesiveness rate and dry weight of thrombus in blood stasis rabbit model; and on rats model of microcirculation disturbance caused by adrenalin, the prostatitis decoction and its capsules had significantly delayed the occurrence of reduction and stopping of blood flow in arterioles. Conclusion: Prostatitis decoction (capsule) was effective in treating chronic prostatitis.