OBJECTIVE： To study the inhibitory effects of rimonabant on cardiomyocyte hypertrophy induced by angiotensinⅡ（Ang Ⅱ） and its mechanisms. METHODS： Rat cardiomyocytes were incubated in 6 well culture plates with density of 2×105 L－1. They were divided into blank control group， model group， positive control group （losartan10 μmol/L）， rimonabant low- concentration， medium-concentration and high-concentration groups （0.1，1.0， 5.0 μmol/L）. The latter 5 groups were cultured with 0.1 μmol/L Ang Ⅱ to induce cardiomyocyte hypertrophy model， and then given relevant concentration of drugs. After cultured with 24 h， diameter and number of spherical cells in each field of vision were observed and measured. The Ca2+ concentration， NO content， NOS activity and protein expression of cannabinoid receptor 1（CB1） in cardiomyocyte were determined. RESULTS： There was no statistical significance in the number of cardiomyocyte （P＞0.05）. Compared with blank control group， the diameter of cardiomyocytes in model group increased， and Ca2+ concentration and protein expression of CB1 in cardiomyocytes were increased significantly； NO content and NOS activity decreased significantly， with statistical significance （P＜0.05）. Compared with model group， the diameter of cardiomyocytes in positive control group， rimonabant low-concentration， medium-concentration and high-concentration groups were decreased significantly， and Ca2+ concentration and protein expression of CB1 in cardiomyocytes were decreased significantly； NO content and NOS activity increased significantly， with statistical significance （P＜0.05）， and the effects of the rimonabant groups were dose-dependent. CONCLUSIONS： Rimonabant can inhibite cardiomyocyte hypertrophy induced by AngⅡ， the mechanism of which may be associated with the decrease of Ca2+ concentration and protein expression of CB1.