Aim To study the effect of insulin-like growth factor-1 receptor antibody on vascular smooth muscle cell proliferation. Methods Seven days after balloon injury,rat's carotid arteries were harvested,smooth muscle cell were cultured in vitro and were evaluated by α-actin immunocytochemical method.The effects of insulin-like growth factor-1 receptor antibody on smooth muscle cell proliferation were observed by BrdU immunocytochemical methods. Results Smooth muscle cell derived from injured arteries shows higher proliferetion compared with those from normal arteries(p<0.01),insulin-like growth factor-1 receptor antibody monoclonal antibody can inhibit smooth muscle cell proliferation concentration dependently(p<0.01). Conclusion Insulin-like growth factor-1 receptor antibody can inhibit smooth muscle cell proliferation,which deserves to be researched deeply.