Objective To evaluate the role of regulatable expression of AT2R gene in vivo on the expression of matrix metalloproteinase 2 (MMP-2) in the neointima after vascular injury in rats by deoxycycline (Dox)-on mesenchymal stem cells (MSCs) transplantation. Methods Two successive rounds of transfection of cultured MSCs were performed with conventional molecular biological methods. MSCs with low background expression and high Dox-induced expression of AT2R gene were deemed double-stable MSCs. Rat models of balloon-induced carotid injury were established. Double-stable MSCs were then transplanted into the site of carotid injury, and Dox was injected via vena caudalis into rats. Pathological study was carried out at 14d and 28d after cell transplantation. AT2R gene expression in the neointima and its effect on the mRNA and protein expression of MMP-2 were analyzed by immunohistochemistry, immunoblotting and RT-PCR. Results Double stable MSCs line with low background expression and high Dox induced expression of AT2R gene was established successfully. Significant AT2R expression was observed after 48h of induction and further increased after 72h and remained stable over 8 weeks. Immunohistochemistry, immunoblotting and RT-PCR indicated that AT2R expression in the neointima was significantly upregulated in Dox group than in control group, MSC group and MSC transfection group (P＜0.01), but the expression of MMP-2 was significantly decreased in Dox group than in other groups (P＜0.01). Conclusion AT2R expression at the site of carotid injury after transfection of our double-stable MSCs were well controlled by Dox. After Dox induces the high expression of AT2R, the expression of MMP-2 in neointima is decreased, which may be one of the mechanisms of regulating AT2R expression in injured vessels to prevent vascular restenosis.