The renin-angiotensin system (RAS) plays a critical role in chronic renal failure associated with heart failure. In the past few years, angiotensin (Ang) (1-7) have been reported to counteract the effects of angiotensin II (Ang II) and were even considered as a new therapeutical target in RAS. The purposes of this study were to examine whether the Ang (1-7) improves the heart function and remodeling of the left ventricle (LV) in mice with 5/6 nephrectomy (NC). We used a 5/6 nephrectomy to induce significant renal dysfunction in wildtype mice (WT). Twelve weeks after NC, WT showed high blood pressure, significant leftventricular dilation and dysfunction, which were accompanied by cardiomyocyte hypertrophy, diffuse interstitial fibrosis and oxidative damage of cardiomyocytes. Exogenous Ang (1-7) injection improved the heart function and remodeling of LV in mice with 5/6 NC accompanied by a reduction in cardiac interstitial fibrosis, inflammatory cytokine expression and oxidative damage levels of cardiomyocytes, decrease in the profibrotic signaling molecule transforming growth factor (TGF)-b and increase in the collagen degradation signaling molecule matrix metalloproteinase (MMP)-2, -9. However, these beneficial effects did not occur in hydralazine-treated mice. These findings suggest that (1) Exogenous Ang (1-7) injection improve the heart function and remodeling of LV in mice with 5/6 NC. (2) These beneficial effects are independent of its anti-blood pressure effect.