To clarify myocardial systolic and diastolic function and possible mechanism of Qiangxin Tang on the model of heart failureMethods:Model of heart failure after myocardial infarction was prepared by left coronary artery ligationAfter 8 weeks，take a lavage treatment every day；After 4 weeks of continuous administration，cardiac hemodynamics parameters were recorded and SERCA2a，RYR2 mRNA level were detected by PCR（FQ-PCR）and SERCA2a，RYR2 protein expression were detected by Western boltResults:compared with control group，cardiac function of model group is lower：hemodynamic parameters LVEDP is increased obviously(P<001),LVSP，+LVdp/dtmax and-LVdp/dtmax absolute values were all lower(P<005)，and the calmodulin SERCA2a and RYR2 mRNA and protein relative expression of model group rats was decreased(P<005)Compared with model group，Qiangxin Tang group could reduce LVEDP levels(P<005),increase LVSP，+LVdp/dtmax and-LVdp/dtmax levels(P<001),and the calmodulin SERCA2a and RYR2 mRNA and protein relative expression of Qiangxin Tang were higherConclusion:Qiangxin Tang can effectively improves cardiac function in heart failure rats; Its mechanism is related with improving calmodulin SERCA2a、RYR2 and improving calcium cycle.