Objective To explore the expressions of transforming growth factor(TGF)-β1 and connective tissue growth factor(CTGF) in viral myocarditis(VM) and the intervention effect of valsarta on them.Methods Fifty-four male Balb/c mice were randomly divided into 3 groups:control group,treatment group and model group.Model group and treatment group established VM model by intraperitoned injecting 0.1 ml CVB3.They were killed on days 7,14 and 28,respectively.Histological cross sections of heart were stained with hematoxylin-eosin and myocardial histopathplogic scores were counted under optical microscope.The expressions of typeⅠand Ⅲ myocardial collagen,TGF-β1 and CTGF were examined by immunohistochemical method and analyzed by using SPSS 11.5 software.Results Compared with control group,histopathplogic scores,the expressions of type Ⅰand Ⅲ myocardial collagen,TGF-β1 and CTGF increased markedly in model group (Pa0.05).Compared with model group,histopathplogic scores,the expressions of type Ⅰand Ⅲ myocardial collagen,TGF-β1 and CTGF decreased significantly in treatment group (Pa0.05).The expression of type Ⅲ myocardial collagen was closely positively correlated with CTGF and TGF-β1,the expression of TGF-β1 was closely positively correlated with CTGF.Conclusions TGF-β1 and CTGF may play important roles in the development of myocardial fibrosis in VM.Valsarta can postpone the development of myocardial fibrosis,and it maybe probably have something to do with decreasing the levels of TGF-β1 and CTGF.