Abstract： Objective To observe the effect of p53 protein on smooth muscle cell(VSMC)in rabbit artery balloon injury.Methods Restenosis model of carotid artery after balloon injury was established in rabbits.30 rabbits were divided into 2 groups,the sham group(n = 6)and the vascular injury group(n = 24).With H.E.staining and automatic image analysis system,we investigated artery morphology alteration and measured the area of arterial intima and media.The expressions of p53 protein were detected by immunohistochemical analysis.Results With H.E.staining and automatic image analysis and immunohistochemistry,the results showed that the expression of p53 was significantly reduced and the intima area was increased in model group compared with the sham group(P ＜0.01).But the expression of p53 in media was remarkably reduced compared with intima(P ＜ 0.01).Conclusions The possible mechanism of preventing arterial restenosis in the balloon injury might be related with p53,which may be through inhibiting neointimal proliferation in arterial restenosis .