Aim To evaluate the effect of silybin on neointimal proliferation of rabbits iliac artery after balloon injury. Methods 22 rabbits were randomly separated into 3 groups including control group, low-dose treatment group and high-dose treatment group. Balloon catheter was used to induce injury to the iliac artery of rabbits in treatment group. Tranilast was given to the rabbits in low-dose treatment group [20 mg/(kg·d)] and high-dose treatment group [40 mg/(kg·d)] once a day from 3 days before operation to 28 days after operation, and then local vessel was harvested for pathological analysis and immunohistochemical staining. Automatic image analysis system was used to detect the changes of intimal thickness, medical thickness, luminal area, and the proliferation index of proliferating cell nuclear antigen (PCNA). Results No significant difference was found between low-dose treatment group and control group in intimal thickness, medial thickness, luminal area and proliferation index of PCNA (p> 0.05 ). The intimal thickness was decreased in high-dose treatment group compared with control group (p< 0.05 ). The luminal area was significantly larger in high-dose treatment group than that in control group (p<0.05). The proliferation index of PCNA was significantly reduced in high-dose treatment group compared with control group (p<0.05). Conclusions Silybin significantly inhibit neointimal hyperplasia and the drug may be used to prevent restenosis.