We studied the function of connexin 43 (Cx43) gene in Xiao Meishan swine bone marrow mesenchymal stem cells (BMSCs) resulting from overexpression. Cx43 eukaryotic expression vector (pEGFP-Cx43) was constructed and transfected into BMSCs by nucleofector, after detecting the transfection efficiency; the expression of Cx43 was verified by RT-PCR, immunofluorescence and western blotting. Furthermore, we detected its cell cycle and apoptosis through flow cytometry. Our results show that pEGFP-Cx43 plasmid was successfully constructed, and green fluorescence in pEGFP-Cx43 transfected BMSCs was highly expressed with 60% transfection efficiency. In transgenic Xiao Meishan swines BMSCs, the expression level of Cx43 mRNA and protein were up-regulated. Meanwhile, the ability of cell proliferation was significantly increased, and the apoptosis rate was significantly reduced. Taken together, Cx43 overexpression could promote the proliferation of Xiao Meishan swine's BMSCs and markedly reduce their apoptosis, which provides evidence for in vivo research.