To study the MMP-2，MMP-9，TIMP-2 and TIMP-1′s function during diabetic cardiomyopathy ventricular remodeling process，as well as the myocardial protective effect and mechanism of Tangxinning.Methods:A total of 36 SD rats were included into the study，9 of them were taken as normal control rats，and the other 27 rats were injected with streptozotocin(STZ).These 27 rats were randomly divided into three groups：a model group and a high dose group of Tangxinning and an equal dose group of Tangxinning.The groups of Tangxinning were given a gavage of Chinese traditional medicine.The groups of model and control were given a gavage of clean drinking water.The experiment lasted 8 weeks.Then，the rats were killed to calculate the left ventricular hypertrophy index and estimate the activities of the T-SOD and MDA in serum.The cardiac histological changes were observed by Masson staining.The protein expression of MMP-2，MMP-9 and TIMP-2 and TIMP-1 in myocardium were detected by immunohistochemical method.Results:After 8 weeks of medication，both high dose group and the equal dose group of Tangxinning could reduce index of left ventricular hypertrophy and MDA，increase the level of T-SOD and the ratio of MMP-9/TIMP-1 and MMP-2/TIMP-2.The myocardial collagen content dropped.Conclusion:Tangxinning may have the effect to readjust the balance of MMP-9/TIMP-1 by improving oxidative stress and weakening TIMP-1 to MMP-9，Then DCM ventricular remodeling effect was reduced.