Abstract: Acetylsalvianolic acid A(ASAA)is a semisynthetic analogue of salvianolic acid A isolated from Danshen(Salvia miltiorrhiza Bunge).Arat middle cerebral artery thrombesis medel wasmade by adding FeCl₃ to the surface of the right middle cerebral artery(MCA).Using this medel,theprotective effects of ASAA on focal cerebral ischemic injury were studied.The neurologic status ofeach rat was carefully evaluated at 4,8 and 24 h after surgery.The cerebral infarction and themorphological changes of brain tissue were examined.Pretreatment with ASAA 50 or 100 mg·kg^-1 iv was shown to significantly reduce the cerebral infarction and attenuate neurological deficits,Thedegree of inhibition of cerebral infarction were 46.5%(P<0.65)and 87.4%(P<0.01),respectively.In pathological examination,pretreatment with ASAA 100 mg·kg^-1 iv,there was nothrombosis or only a little thrombosis in MCA,The extent of tissue ischemia was much less than thatof control.These results indicate th8t the beneficial effects of ASAA on focal cerebral ischemic rats subjected to middle cerebral artery thrombosis may be related to its antithrombotic effect。