Abstract：Objective：To discuss the effect of modified Guizhi Gancao Longgu Muli decoction on ventricular premature (VP) beats and levels of nitric oxide(NO) and endothelin-1(ET-1) in serum in rats with coronary heart disease. Methods：A total of 30 rats were randomly divided into the Chinese medicine group，the Chinese patent medicine group，the western medicine group，the model group，and the blank group，six rats in each group. Except for the blank group，the other groups were fed with high-fat diet and injected with pituitrin to establish the model of VP in coronary heart disease. After successful establishment，the Chinese medicine group was given gastric perfusion of modified Guizhi Gancao Longgu Muli decoction at a dose of 6.3 g/kg；the Chinese patent medicine group was given gastric perfusion of compound Danshen dripping pills at a dose of 85 mg/kg；the western medicine group was given simvastatin at a dose of 2.1 mg/kg by gavage；the model group and the blank group were given normal saline at a dose of 20 mL/kg by gavage. All groups were given gastric perfusion once a day for 12 weeks. The 24- hour dynamic electrocardiogram was recorded before establishment and after the last gastric perfusion. The ST segment of electrocardiogram，the level of blood lipid，and the condition of premature beats in each group were observed. The level of NO was measured by nitrate reductase method，and the level of ET-1 was detected by enzymelinked immunosorbent assay. Results：When compared with those in the blank group 24 hours after the last administration， in the model group，the ST segment，the levels of low-density lipoprotein cholesterol(LDL-C) and high-density lipoprotein cholesterol(HDL-C)，triglyceride(TG)，total cholesterol(TC)，and ET-1 were increased(P＜0.05)；and the latency of VP was shortened(P＜0.05)；the level of NO in serum was decreased(P＜0.05)，and the duration of VP was prolonged. Compared with those in the model group， in the Chinese medicine group， the Chinese patent medicine group， and the western medicine group，the ST segment，the levels of LDL-C，TG，TC and ET-1 were decreased(P＜0.05)；and the latency of VP was prolonged(P＜0.05)；the levels of HDL-C and NO in serum were increased(P＜0.05)；the duration of VP was shortened (P＜0.05). Compared with those in the Chinese medicine group， in the Chinese patent medicine group and the western medicine group，the ST segment，the levels of LDL-C，TG，TC，HDL-C and ET-1 were increased，and the latency of VP was prolonged(P＜0.05)；the levels of NO in serum were decreased(P＜0.05). Conclusion：Modified Guizhi Gancao Longgu Muli decoction can promote myocardial blood supply and regulate the level of blood lipid in rats with coronary heart disease and VP. Besides，it can significantly enhance the level of NO in serum，and reduce the level of ET- 1，which has good preventive effect on VP in coronary heart disease.