Non-viral vector, pCMV-Pth, with full-length human parathyroid hormone (prepro-hPTH) cDNA was constructed and delivered into the ovariectomized mouse quadriceps to explore the effects of electroporational gene transfer of PTH on the bone. The expression of hPTH in the transfected mice was detected by RT-PCR and radioimmunoassay. Mechanical testing and the analysis of bone mineral content demonstrated the improvement of bone properties. These results suggest that the electroporational gene taransfer of parathyroid hormone might be a promising method to prevent the bone loss in the postmenopausal women.