Objective:To observe the effect of “Yangxin Decoction” on the serum levels of brain natriuretic peptide (BNP) and left ventricular ejection fraction (LVEF) in rats with chronic heart failure(CHF). Methods60 SD male rats were chose. Among which 10 rats were randomly selected as blank control group,the remaining 50 rats were treated with adriamycin by intraperitoneal injection at the dose of 4 μg/g/week. After 6 weeks the heart function of all rats were measured,and the model of CHF was established successfully with LVEF≤60%. The successful model rats were randomly divided into the model control group, Yangxin decoction group and captopril group, 14 in each group. Yangxin Decoction group was treated with Yangxin decoction extract at the dose of 2.34 g·kg-1·d-1; the captopril group was treated with captopril at the dose of 2.25 μg·g-1·d-1,and the blank control group and model control group were treated with equal volume of distilled water. After 4 weeks,the level of LVEF and serum BNP of all rats were measured,the morphology of myocardial tissue was observed by Hematoxylin-Eosin (HE) staining.  Results:For BNP and LVEF,the differences between the blank control and model control group were statistically significance (P<0.01); the differences between the model control and Yangxin Decoction group or captopril group were statistically significance (P<0.01)；there were no statistically significant difference between the Yangxin decoction and captopril group (P>0.05). HE staining showed that in the blank control group myocardial cell morphology,ransverse longitudinal lines and cytoplasm were normal,muscle fibers arranged in neat,cytoplasm was homogeneous and no inflammatory cell infiltration and cell proliferation were in the myocardium; while in model group myocardial cells are wavy and the gap widened and swelled,inflammatory cell infiltration,part of the vacuole degeneration,myocardial fiber arrangement disorder, interstitial edema and even bleeding were observed. It can be seen mild myocardial fiber granular degeneration in the Yangxin decoction and captopril group,and there was no obvious difference between two groups.  Conclusion:“Yangxin Decoction” could reduce the level of serum BNP and improve LVEF of rats with CHF,the efficacy was comparable with captopril.