Objective:To observe the intervention of Zhilong Huoxue Tongyu capsale on aspirin resistance and its mechanism MethodS:60 patients with aspirin resistance were randomly divided into increasing aspirin dosage group,given Aspirin 300 mg/d;and Zhilong Huoxue Tongyu capsule group,given Zhilong Huoxue Tongyu capsule 1.6g,tid.After 4 consecutive weeks;PAG,TXB₂,6-K-PGF1αand drug safety were observed and compared. Results:The effective rate in treatment group was significantly higher;AA and ADP induced platelet aggregation rate and its decreased value were significantly lower than that of the control group.After treatment TXB₂ increased significantly in both groups（P<0.01）.6-K-PGF₁αin Zhilong Huoxue Tongyu capsule group was higher than increaseing group in aspirin dosage（P<0.05）;after treatment,it was significantly lower in increasing aspirin dosage group（P<0.01.） After treatment,the amount of TXB₂/6-K-PGF₁αwas lower in both groups（P<0.01,0.05）, The incidence of adverse drug reactions was significantly lower in treatment group than in control group.Conclusion: Zhilong Huoxue Tongyu capsule intreating aspirin resistance has better efficacy and safety,which may relate to the decrase of TXB₂,increase of 6-K-PGF₁α,and the decrease of TXB₂/6-K-PGF₁αthus effectively improving the AR.