To explore efficacy and mechanism of Compound Danshen Dripping Pill. Methods:A total of 214 patients with CHD were selected, including 44 patients with aspirin resistance (AR) and 170 patients with Aspirin semi-resistance (ASR). Another 828 patients with CHD were selected, including 448 males and 380 females, age between 40～89 (61±11.18) years old. On top of Aspirin, Compound Danshen Dripping Pill was given, 10pills per time, 3 times a day. Platelet aggregation rate was assessed prior to and after 2-week treatment. Results:Compared with the platelet aggregation rate of AS group, the rates of AR group, ASR group and AR+ASR group were significantly higher. Among 214 patient of AR or ASR, 103 patients reached the level of AS (48.13%), 42 patients had the rate dropped by 1/5 but still higher than the AS. Total effective rate equaled to 67.76%, without abnormal findings in hematology, liver function, kidney function. Conclusion: Compound Danshen Dripping Pill can reduce platelet aggregation rate in patients of aspirin resistance, possibly through multi-targeting, which needs further investigation.