Abstract： Objective： To observe the clinical effect of Yangyin Huayu Prescription combined with routine western medicine for tachyarrhythmia. Methods： A total of 103 cases of patients with tachyarrhythmia were selected as study objects and were divided into the observation group and the control group according to the random number table method，with 51 and 52 cases in each group respectively. The control group was treated with routine western medicine， and the observation group was additionally treated with Yangyin Huayu Prescription based on the treatment of the control group. The changes in electrocardiogram indexes， Chinese medicine syndrome scores and serological indexes before and after treatment as well as the clinical effects in the two groups were compared. Results：The total effective rate was 94.12% in the observation group， higher than that of 80.77% in the control group(P＜0.05). After treatment， heart rates， ST- segment descending amplitudes and QRc intervals in the two groups were decreased and the PR intervals were increased when compared with those before treatment(P＜0.05)；the heart rate，ST- segment descending amplitude and QRc interval in the observation group were lower and the PR interval was higher than those in the control group(P＜0.05). After treatment，TCM syndrome scores in the two groups were decreased when compared with those before treatment(P＜0.05)，and the Chinese medicine syndrome score in the observation group was lower than that in the control group(P＜0.05). After treatment，the levels of thromboxane-B2(TXB2) and endothelin-1(ET-1) in the two groups were decreased when compared with those before treatment，and the levels of nitric oxide(NO) were increased(P＜0.05)； the levels of TXB2 and ET-1 in the observation group were lower and the level of NO was higher than those in the control group(P＜0.05). Conclusion： The therapy of Yangyin Huayu Prescription combined with routine western medicine for tachyarrhythmia has a significant effect， which can relieve clinical symptoms，improve electrocardiogram indexes and endothelial function.