Abstract：Objective：To observe the clinical effect of Yixin Decoction on chronic heart failure (CHF) and its effect on renin- angiotensin- aldosterone system (RAAS). Methods： A total of 116 CHF patients were included and divided into the observation group and the control group according to the random number table method， with 58 cases in each group. The control group was given routine western medicine for treatment，and the observation group was additionally treated with Yixin Decoction based on the treatment of the control group. After 8 weeks of treatment，the clinical effects were evaluated；the levels of indexes of heart function，including left ventricular ejection fraction (LVEF)，stroke volume (SV) and cardiac output (CO)， indexes of heart rate variability (HRV)， including standard deviation of NN intervals (SDNN) within 4 hours， root mean square of successive differences (RMSSD) between adjacent R- R intervals within 24 hours and proportion of number of times adjacent NN intervals differing by more than 50 ms (PNN50) of total sinus beats，and RAAS indexes，including angiotensin-Ⅱ(Ang-Ⅱ)，aldosterone (ALD) and plasma renin activity (PRA) before and after treatment were compared between the two groups. Results： After treatment，the total effective rate was 93.10% in the observation group and 77.59% in the control group， the difference being significant (P＜0.05). After treatment，the levels of LVEF，SV and CO in both groups were increased when compared with those before treatment (P＜0.05)，and the above three levels in the observation group were higher than those in the control group (P＜0.05). After treatment， the levels of SDNN，RMSSD and PNN50 in both groups were increased when compared with those before treatment (P＜0.05)，and the above threelevels in the observation group were higher than those in the control group (P＜0.05). After treatment， the levels of Ang- II， ALD and PRA in both groups were decreased when compared with those before treatment (P＜0.05)， and the above 3 levels in the observation group were lower than those in the control group (P＜0.05). Conclusion：The therapy of Yixin Decoction combined with routine western medicine has a significant curative effect on CHF， which can effectively decrease the RAAS activity of patients，improve the HRV and enhance the heart function.