Objective To investigate the effects of fluvastatin on expression of connective tissue growth factor (CTGF)in the myocardium of diabetic rats. Methods Thirty-two Sprague-Dawley rats were randomized into four groups: normal control, untreated and STZ-induced diabetic rats, and diabetic rats treated with low-dose and high-dose fluvastatin.After 12 weeks′ intervention, body weight as well as the weights of both whole heart and its left ventricle were measured to calculate the ratio of heart weight to body weight (H/B) and the left ventricle mass index (LVMI).The mRNA expression of CTGF, transforming growth factor β1 (TGF-β1), fibronectin (FN),collagen type Ⅲ (ColⅢ) in the myocardium were detected by RT-PCR. Results Compared with the normal control group, the untreated diabetic group showed the increased (all P<0.05) H/B, LVMI and mRNA expressions of CTGF, TGF-β1, FN, and Col Ⅲ in the myocardium. In addition to the effective regulation of lipid metabolism, fluvastatin treatment could obviously reduce the increment of H/B and LVMI(P<0.05～0.01), and suppress the mRNA expressions of CTGF, TGF-β1, FN, and Col Ⅲ in the myocardium of diabetic rats(P<0.01).The down-regulation of CTGF was more significant than that of TGF-β1.All these effects were in dose dependent way. Conclusions Fluvastatin inhibits extracellular matrix accumulation in the myocardium of diabetic rat.Down-regulating the overexpression of CTGF in diabetics is an underlying mechanism of fluvastatin in the cardiac protection.