Objectives To treat myocardial infarction with MSCs transplantation combined with VEGF gene therapy in rabbits and to study its mechanisms. Methods Forty-eight rabbits were randomly divided into MI group (n=12), MSCs group (n=12), VEGF group (n=12), MSCs+VEGF group (M+V group, n=12). Rabbit myocardial infarction models were founded by the ligation of left anterior descending artery. 107 MSCs were injected into the infarct-zone in four sites 2 weeks later in MSCs and M+V group. phVEGF gene were injected in infarct-zone in VEGF group and MSCs transfected with phVEGF gene were injected in M+V group. Heart function including LVEDP, LVSP, LVDP, -dp/dtmax, +dp/dtmax, were measured in vivo. The hearts were harvested at 4 weeks after transplantation and sectioned for HE stain,immunohistochemical stain of BrdU and Ⅷ factor antigen. Results The left ventricular hemodynamics parameters showed that heart function were improved more in M+V group than MSCs group, MI group and VEGF group. The numbers of BrdU positive cells in M+V group(61±8)were more than in MSCs group (44±8,P＜0.01). The numbers of vessels in infarcted zone were more in M+V group (49±8) than in MSCs group (33±6, P＜0.01)、VEGF group(30±8,P＜0.01)and MI group (18±4,P＜0.01). Conclusions VEGF-expressing MSCs transplantation could improve heart function after myocardial infarction, and they were more effective than sole MSCs transplantation. Keeping more MSCs survival and ameliorating the blood supply of infarct-zone might be involved in the mechanisms.