AimTo investigate the effect of hydrogen sulfide on cardiac remodeling in rats, after the two-kidneys-one-clip (2K1C) model built.Methods 34 male Sprague-Dawley (SD) rats were randomly divided into four groups: control group, sham-operated group, 2K1C model group and hydrogen sulfide (H₂S) group.Systolic blood pressure (SBP), the left ventricle weight/body weight (LVW/BW), the heart weight/body weight (HW/BW) and the left ventricle weight/heart weight (LVW/HW) were measured to assess cardiac remodeling.The diameter, the cross-sectional area of the myocardial cells were evaluated by HE stain.Collagen deposition were detected by Masson stain.Angiotensin Ⅱ receptor-1 (AT1) expression in the myocardial cells were assessed by immunohistochemistry.ResultsCompared with the control group, SBP increased persistently in 2K1C group and LVW/BW, HW/BW, LVW/HW increased accordingly. While in the H₂S group, SBP elevated transiently and tended to decrease afterward.LVW/BW, HW/BW, LVW/HW decreased in H₂S group compared with 2K1C group.HE stain showed significantly milder myocardial injury in H₂S group than that in 2K1C group.Masson stain showed less collagen deposition in H₂S group than that in 2K1C group.The expression of AT1 receptor was up-regulated in the 2K1C group, which can be reversed by treatment with H₂S.ConclusionH₂S can attenuate cardiac remodeling in 2K1C rats by down-regulating AT1 expression.