Abstract: Objective To study the expression of Actinin, alpha 2 (ACTN2), α-actin and Troponin T type 2 (TNNT2) in rat bone marrow-derived mesenchymal stem cells (rBMSCs) induced by low frequency pulsed electromagnetic fields (PEMFs). Methods The rBMSCs were isolated by adherence method and the third-generation of the rBMSCs were randomly divided into PEMFs groups, 5-Azacytidine groups (5-Aza), PEMFs +5-Aza group and control groups. PEMFs groups with complete medium were exposed to 50 Hz, 1 mT PEMFs for 30 min every day, lasting for 10 d, 15 d and 20 d, respectively. 5-Aza groups were induced by 10 μmol/L 5-Aza for 1 day, then the medium was changed to complete medium without 5-Aza. PEMFs +5-Aza group were firstly induced by 10μmol/L 5-Aza for 1 day, and then were exposed to PEMFs according to the way of PEMFs group. And control groups were only cultured with complete medium. rBMSCs' growth status and morphological features were observed by inverted phase microscope. The mRNA expressions of ACTN2 and TNNT2 were determined by real-time fluorescent quantitation PCR. And the protein expression of the ACTN2, α-actin and TNNT2 were detected with Western blot method. Results The result showed that the mRNA expression level of the ACTN2 and TNNT2 and the protein expression level of the ACTN2, α-actin and TNNT2 were significantly higher in the PEMFs group, 5-Aza group and PEMFs+5-Aza group when compared with the control group. Conclusion PEMFs may induce rBMSCs differentiation into cardiomyocyte-like cells in vitro.