【Abstract】 Objective To evaluate the mechanisms of endogenous stem cell homing improvement by cytoplasmic and nuclear membrane double targeted cationic microbubbles carrying SDF1α gene combined with ultrasonic irradiation.Methods The double targeted cationic microbubbles carrier system and cationic microbubbles carrying SDF1α gene were constructed. SDF1α gene was transfected to the human umbilical vein endothelial cell in vitro and efficiency of SDF1α gene transfection was detected including the SDF1αplasmid cellularimport rate, the SDF1αplasmidnuclear import rate and gene expression of SDF1α protein. Then the myocardial infarction rabbits models were built and divided randomly into A group, B group and C group. A group was treated with double targeted cationic microbubbles carrying SDF1αgroup. B group was treated with cationicmicrobubbles carrying SDF1αgroup. C group was control group. 3 days and 4 weeks after gene transfection, gene expression of SDF1α gene, stem cell markers and angiogenesis effects were detected respectively.Results In vitro, under the ultrasonic irradiation, compared with the cation microbubbles carrying SDF1α system, there was no difference in the SDF1αplasmidcellular import rate between the cation microbubbles carrying SDF1α system and the double targeted cationic microbubbles carrying SDF1α system, while the latter had the higher the SDF1αplasmidnuclear import rate and gene expression of SDF1α protein. In vivo, compared with thecationic microbubble carrying SDF1αgroup and control group, SDF1α protein expression, stem cell marker positive staining and capillary density in rabbits’ myocardium increased significantly in the double targeted cationic microbubble carrying SDF1αgroup.Conclusion Cytoplasmic and nuclear membrane double targeted cationic microbubbles carrying SDF1α gene combined with ultrasonic irradiation can improve the SDF1α gene transfection efficiency effectively, which induces the sufficient expression of SDF1α protein, playsa role of stem cells inducer, and then promotes endogenous stem cells homing and angiogenesis.