Objective To determine the effects of Fuzheng Huayu (FZHY) capsule in improving myocardial fibrosis and remodeling following sustained pressure-overload cardiac hypertrophy in Rats.Methods Sustained pressure-overload cardiac hypertrophy in rats was made by constricting suprarenal abdominal aorta.The heart structural changes of eight weeks and four weeks model rats, using echocardiographic techniques, and then parameters involving in myocardial fibrosis including Collagen Ⅰ,Collagen Ⅲ, of 4 weeks and 8 weeks model rats were evaluated using pathologic technique.The rats were divided into four groups including model group, sham-operated group, Captopril group, and Fuzhenghuayu capsule group, then evaluating the parameters involving in myocardial fibrosis including heart structure,Collagen I, Collagen Ⅲ, TGF-β1 mRNA gene expression, and TGF-β1 protein of 4 weeks and 8 weeks model rats using pathologic techniques.Results Compared with model group, IVSTd, LVPWTd, LVDd,in Fuzheng Huayu group became significantly decreased.Fhuzheng huayu can lessen collagen type 1 and 3deposition on myocardium tissue P<0.01, however Captopril group has the best effect in inhibiting type Ⅰ,and type Ⅲ collagen, P<0.01.There was a positive correlation between the left ventricular ejection fraction (EF %) and Collagen Ⅲ/Ⅰ ratio.Conclusion Development in the prevention of fibrosis can be achieved by combining advantages of traditional Chinese medicine and Western medicine.