Objective：To investigate the effects of acetylation of histone H3 on the regulation of heart development-related transcription factor insulin gene enhancer protein 1（Islet-1）. Methods：Cardiac progenitor cells were cultured in vitro and were treated with histone deacetylase inhibitor suberoylanilide hydroxamic acid（SAHA） at concentration of 0.5，1.0，2.0，4.0 μmol/L. Methyl thiazoyl tetrazolium（MTT） assay was used to detect the effect of SAHA on cell proliferation and to select suitable intervention concentration. Western blot was applied to detect the acetylation of histone H3 and Real-time PCR was employed to measure the mRNA expression of Islet-1. Chromatin Immunoprecipitation（ChIP）Real-time PCR was used to measure the level of the acetylation of histone H3 in promoter region of Islet-1. Results：The cell proliferation rate of SAHA was increased in 0.5 μmol/L and 1.0 μmol/L group than in control group but without siganificant difference（P >0.05）. No difference in the cell proliferation rate was found between SAHA 2.0 μmol/L group and control group（P >0.05）. The cell proliferation in SAHA in 4.0 μmol/L group was greatly affected（P<0.05）.Western blot showed that the acetylation of histone H3 was increased by 7.23 fold in SAHA 2.0 μmol/L group after 48 h（P<0.05）. The expression of Islet-1 was increased by 4.68 fold（P<0.05），and the level of the acetylation of histone H3 in promoter region of Islet-1 was increased to 2.08 fold（P<0.05） compared with those in control group. Conclusion：The expression of Islet-1 can be promoted by increasing of the acetylation of histone H3 in promoter region of Islet-1. The expression of Islet-1 is regulated by the acetylation of histone H3 in cardiac progenitor cells.