Abstract: Objective To investigate the effect of Akt on cardiomyocyte hypertrophy induced by hydrogen peroxide(H2O2). Methods The neonatal rat cardiomyocytes cultured in primary generation were treated with low concentrations of H2O2. The cardiomyocyte hypertrophy was evaluated by the determination of average cell volume and protein content.The effccts of Akt inhibitor on cardiomyocyte hypertrophy induced by H2O2 was observed. Western blot was performed to examine the phosphorylation of Akt induced by H2O2. Results H2O2 at 10 or 50 μmol/L stimulated cardiomyocyte enlargement as measured by cell volume and the protein content per cell.The inhibitor of Akt inhibited the hypertrophic response of cardiomyoctes stimulated by H2O2. H2O2 increased the level of Akt phosphorylation in cardiomyocytes, while that is suppressed by the inhibitors of PI3K(phosphoinositide 3-kinase). Conclusion Akt signaling is involved in cardiomyocyte hypertrophy induced by H2O2.