The inhibitory effect of astilbin on transplant arteriosclerosis in murine model of thoracic aorta transplantation was examined.Model of rat thoracic aorta transplantation was established.Ninety rats were divided into three groups.In isograft group,the thoracic aorta of Brown Norway (BN) rat was anastomosed with the abdominal aorta of another BN rat.In allograft group,the thoracic aorta of BN rat was anastomosed with the abdominal aorta of Lewis rat.In astilbin group,the rats receiving allo-transplantation were given astiibin 5 mg/kg per day for a time of 28 days.The donor thoracic aorta and the recipient abdominal aorta were anastomosed by means of a polyethylene cannula (inner diameter:1.5 mm,length:3 mm length).The grafts were histologically examined for structural changes.The areas of arterial lumen and endatrium were calculated.Our results showed that,in the allograft group,28 days after aliografting,conspicuous proliferation of smooth muscles and infiltration with a great number of inflammatory cells were found in the tunica intima and tunica media.Astilbin significantly inhibited the proliferation of smooth muscles and ameliorated the infiltration of inflammatory cells thereyby prevent against the development of transplant arteriosclerosis.It is concluded that asltilbin can effectively prevent the development of arteriosclerosis in allotrausplant by inhibiting the proliferation of smooth muscles and inhibit the proliferation of smooth muscles in tunica of intima and media and reducing infiltration of the inflammatory cells.