AIM: To study the protective effect of non-mitogenic human acidic fibroblast growth factor (FGF) on cardiac oxidative injury in vivo.METHODS: Ventricular cardiomyocytes were isolated from 1- to 3-d-old neonatal SD mice and cultured in Dulbeccos minimum essential medium supplemented with 15% fetal bovine serum under an atmosphere of 50 mL/L CO2-95% air at 37 ℃, as well as assessed by immunocytochemical assay. We constructed the cardiomyocyte injury model by exposure to a certain concentration of H2O2.Cellular viability, superoxide dismutase (SOD) activity,leakage of maleic dialdehyde and anti-apoptosis effect were included to evaluate the cardiac protective effect of non-mitogenic human acidic FGF.RESULTS: Over 50% of the cardiomyocytes beat spontaneously on the 2nd d of culture and synchronously beat after being cultured for 3 d. Forty-eight hours after plating was completed, the purity of such cultures was 95% myocytes, assessed b,y an immunocytochemical assay. Cellular viability dramatically decreased with the increasing of the concentration of H2O2. Non-mitogenic human acidic FGF showed significant resistance to the toxic effect of H2O2, significantly increased the cellular viability as well as the activity of SOD, and dramatically decreased the leakage of maleic dialdehyde as well as the cellular apoptosis rate.CONCLUSION: Hydrogen peroxide shows strong cytotoxicity to the cultured cardiac myocytes, and non-mitogenic human acidic FGF shows strong cardio-protective effect when exposed to a certain concentration of H2O2.