Abstract: To investigate the method by which rabbit mesenchymal stem cells（MSCs）could be induced to cardiomyocytes and effect, MSCs isolated from rabbit femoral bone marrow were cultured in cell culture medium and in medium with 5Azacytidine（5Aza）. Whether the induced cells expressed cardiacspecific protein αactin and cardiac troponin T（cTnT） was identified by immunocytochemistry and inverted microscope, and the differentiation rate in each group was calculated. The results showed that some MSCs gradually increased in size and formed a sticklike appearance after inducation in experimental group, one month after treatment, most of the long sticklike cells connected with adjoining cells and began to form myotubelike structures, the direction of the cells arraying was similar gradually. Cardiac cellspecific protein αactin and cTnT expressed positively, the expression rate of cardiac cellspecific protein was different after MSCs was induced by different concentration 5Aza, of which 10 μmol·L-1 5Aza was the optimal concentration. These results indicate that MSCs can be induced to cardiomyocytes by 5Aza in vitro, and which have the characteristics of cardiomyocytes in structure. The optimal concentration of 5Aza inducing MSCs to cardiomyocytes is 10 μmol·L-1.