Objective:To observe the effect of Luqi Granule on cardiac function and serum endotoxin (lipopolysaccharid, LPS) level in rats with acute myocardial infarction (MI). Methods60 healthy adult male Wistar rats were randomly assigned into sham operation group, model group and vancomycin group (0.075 g·300 ml-1·d-1), low-dose Chinese medicine group (0.25 ml·kg-1·d-1), middle-dose Chinese medicine group (0.5 ml·kg-1·d-1) and high-dose Chinese medicine group (0.75 ml·kg-1·d-1), 10 rats in each group. Except the sham operation group, MI model was established with rats in the other 5 groups by ligating the left anterior descending coronary artery. The sham operation group received the same procedure except that the coronary artery was not ligated. After successful modeling, each drug group was given the corresponding drug, and the sham operation group and the model group were given an equal volume of 0.9% NaCl solution for 6 weeks. Cardiac function [left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (FS)], serum LPS level and myocardial histopathology were observed.  Results:①=1\*GB3Compared with the sham operation group, the model group had lower LVEF and FS values (P<0.05) and a higher serum LPS level (P<0.05). ②=2\*GB3Compared with the model group, the serum LPS level decreased in the vancomycin group and the middle- and high-dose Chinese medicine groups (P<0.05); the LVEF and FS values increased in the middle- and high-dose Chinese medicine groups (P<0.05). ③=3\*GB3Compared with the vancomycin group, the LVEF and FS values increased in the middle- and high-dose Chinese medicine groups (P<0.05). ④=4\*GB3Compared with the low-dose Chinese medicine group, the LVEF and FS values increased and the serum LPS level decreased in the middle- and high-dose Chinese medicine groups (P<0.05). ⑤=5\*GB3There were no significant differences in cardiac function and serum LPS level between the middle- and high-dose Chinese medicine groups (P>0.05).  Conclusion:Luqi granule improves the cardiac function of rats with acute MI and reduces inflammatory area of myocardial tissue. The mechanism may be related to decrease in serum LPS level and maintenance of cardiac homeostasis.