Objective To investigate the transfection efficiency of the recombinant human bone morphogenetic protein- 2（hBMP- 2） gene in targeted cells by ultrasound- mediated microbubble destruction. Methods NIH3T3 cells′ anabiosis was completed and went down to the 3rd or 4th generation, and cultured in 6 well plates. The cells were divided into 2 groups: Plasmid DNA and LipofectamineTM 2000 group（liposome group）, plasmid DNA and ultrasound and microbubble group（ultrasound- mediated microbubble destruction group）. Plasmid DNA was transfected into cells with liposome or ultrasound and microbubble. 24- 48 hours later, the transfection efficiency and the concentrations of hBMP- 2 were measured with fluoresence microscope and enzyme - linked immunosorbent assay（ELISA） respectively. The data were analyzed by curve fitting and t- test of SPSS 11.5. Results The transfection efficiency rate was（7.30± 1.58）% in liposome group, compared with （11.77±3.16）% in ultrasound- mediated microbubble destruction group（P
