Aim To observe the effect of flavonoids from Cuscuta Chinensis on myocardial cell apoptosis and the related gene expression in ischemic/reperfused myocardial infarction. Methods The left anterior descended coronary artery was ligated for 30 min and reperfused for 2 h to make ischemia-reperfusion injury model.50 SD rats were randomly divided into the sham operation group,ischemia-reperfusion group,the low and high dose groups of flavonoids from Cuscuta Chinensis and isosorbide dinitrate group.Creatine kinase(CK) and lactate dehydrogenase(LDH) were assayed.The apoptotic index(AI) was analyzed by TUNEL staining.The protein expression of Bcl-2 and Bax were measured by immunohistochemistry and Western Blotting in each group,the ratios of Bcl-2 and Bax were calculated. Results Compared with the sham operation group,the ischemia-reperfusion group of enzymes CK and LDH,AI,and Bcl-2 and Bax protein expression were significantly higher(P<0.01);The enzyme CK and LDH,and AI in the low and high dose group of flavonoids from Cuscuta Chinensis were decreased compared with those of the ischemia-reperfusion group(P<0.01).The expression of Bcl-2 was increased and the expression of Bax was decreased(P<0.01).The isosorbide dinitrate group showed no significant difference when compared with the high dose group of flavonoids from Cuscuta Chinensis(P>0.05). Conclusion The pretreatment of flavonoids from Cuscuta Chinensis could dose-dependently decrease enzymes CK,LDH levels,increase the expression of Bcl-2 protein and Bcl-2/Bax,reduce the expression of Bax protein,and inhibit the apoptosis of myocardial cell.The therapeutic effects was similar to isosorbide dinitrate.