Objective To explore the role of histone modification in the MafA gene transcription expression and to comparing the differences of histone modifications of MafA genes promoter in various cell types of mouse. Method The promoter histone modification status of MafA and MLH1 genes in NIT-1 cells，NIH3T3 cells and mouse embryonic stem cells were measured by chromatin immunoprecipitation-real time PCR methods. The expression of these genes in the three cell lines were measured by realtime RT-PCR. The relation between histone modifications and genes expressions were analysed. Result (1)Compared with mES cell，there were higher H3K4m3 and lower H3K9m3 modification levels in the promoter of MafA gene in NIT-1 cell(P < 0. 05) . There were higher H3K9m3 and lower H3K4m3 modification levels in the promoter of MafA gene in NIH3T3 cells(P < 0. 05) . (2) MafA gene transcription expressed only in NIT-1 cells. There was the Pearson correlation between MafA gene expression and H3K4m3 modification( Coef. 0. 995) . And Pearson correlation was also between MafA gene expression and H3K9m3 modification (Coef. -0. 751) . (3) There was not correlation between housekeeper MLH1 genes expression and histone modification. Conclusion H3K4m3 and H3K9m3 modification could coordinated participate to regulation and control expression of MafA gene. It is great significant to the differentiation of βcells from ES cells.