Objective To investigate the influence of Bushenhuoxue formula on cardiac function in rat models of acute myocardial infarction（ AMI） and its possible mechanism. Method Sixty Wistar rats were randomly divided into six groups

which were the sham-operation group

AMI model group

positive drug control group

and high-dose

medium-dose and low-dose Bushenhuoxue formula groups. The rat models of myocardial infarction were established by ligation of the anterior descending coronary artery in all groups except for sham-operation group. The high-dose

medium-dose and low-dose Bushenhuoxue formula groups were gavaged with 10 g /（ kg·d）

5 g /（ kg·d）

or 2. 5 g /（ kg·d） of crude drug of Bushenhuoxue formula

respectively; The positive drug control group was gavaged with 0.2 g /（ kgd） of enalapril; and both the sham-operation group and AMI model group were give the same volume of saline. 14 days after treatment

thickness of left ventricular anterior and posterior wall at end-diastole（ LVAWd and LVPWd）

as well as left ventricular internal dimension at end-diastole and end of systole（ LVIDd and LVIDs） were measured with high resolution ultrasound imaging system. Left ventricular end diastolic volume（ LVEDV）

left ventricular end systolic volume（ LVESV）

ejection fraction（ EF）

fractional shortening（ FS）

and systolic volume（ SV） were calculated to assess the change in structure and function of rat hearts in each group. Serum levels of angiotensin Ⅱ（ Ang Ⅱ） and endothelin-1（ ET-1） were detected with enzyme-linked immunosorbent assay（ ELISA）.Result Compared with the model group

LVAWd increased significantly（ P < 0. 05 or P < 0. 01）

and LVIDd and LVEDV showed a trend of decrease but with no significant difference（ P > 0. 05） in all Bushenhuoxue formula groups; Levels of EF and FS were increased significantly in Bushenhuoxue formula high dose group and positive drug control group（ P < 0. 01）; Levels of Ang Ⅱ was reduced significantly（ P < 0. 01）; and levels of ET-1 showed a downward trend but with no significant difference in all Bushenhuoxue formula groups（ P > 0. 05）. Conclusion Bushenhuoxue formula can inhibit left ventricular remodeling and improve heart function by reducing level of Ang Ⅱand adjusting the level of ET-1 in early phrase of acute myocardial infarction.