OBJECTIVE: To observe the intervention effects of Jiashen formula extractum on hydrogen peroxide(H2O2)-induced apoptosis of H9c2 cardiomyocytes, and to investigate its mechanism. METHODS: MTT assay was used to investigate the effects of 400, 200, 100, 50, 25 μmol/L H2O2 and 3.0, 1.8, 0.9, 0.3, 0.1 mg/mL Jiashen formula extractum on the activity of H9c2 cardiomyocytes. H9c2 cardiomyocytes were divided into normal group, model group and Jiashen formula group. Model group and Jiashen formula group were given 50 μmol/L H2O2 to induce oxidative stress injury except that normal group was cultured with corresponding culture medium. Jiashen formula group was given 0.3 mg/mL Jiashen formula extractum for intervention on the basis of model group. Cell morphology was observed by fluorescence microscope through DAPI dye. The apoptosis rate was detected by flow cytometry. Fluorescence quantitative RT-PCR was used to detect mRNA expression levels of Caspase-3, Bax and Bcl-2 in cells; Western Blot assay was used to determine the protein expression levels of Caspase-3, Bax and Bcl-2. RESULTS: 50 μmol/L was the most suitable modeling concentration of H2O2; 0.3 mg/mL was the most suitable intervention concentration of Jiashen formula extractum. Compared with model group, cells in Jiashen formula extractum group were significantly improved in morphology and reduced in apoptosis rate; mRNA and protein expression levels of Caspase-3 and Bax were significantly reduced, and those of Bcl-2 were significantly increased (P<0.05). CONCLUSIONS: Jiashen formula extractum shows significant inhibitory effect on H2O2-induced apoptosis of H9c2 cardiomyocytes, the mechanism of which may be associated with down-regulation of Caspase-3 and Bax expression and up-regulation of Bcl-2 expression in cardiomyocytes.