Objective To investigate the effect of tetram ethyloyrazine (TMP) on the pathological changes of cerebral vasospasm(CVS) after subarachoid hemorrhage(SAH) in rats.Methods 60 healthy adult SD rats were randomly divided into four groups (n=15).In group A: normal Saline was injected in the cisterna magna; in group B, C, D: autologous arterial was injected in the cisterna magna,and added NS 2ml or nimotop 0.1mg or TMP hydrochloride 20mg intraperitoneal injection every day.Five animals in each group were sacrificed and the brain samples were harvested at day 1, day 4 and day 7 respectively.Results The structure of basilar artery(BA) was normal in group A.The vasospasm of BA was found in group B at day 1 and day 4, especially at day 7.The vasospasm in group C was remarkably remitted compared with that in SAH group at the same period.The vasospasm and vsacular wall thickening and expression of NF-кBp65 and Cox2 in group D was remarkably remitted compared with that in group B and C.Conclusions TMP may has the potential ability to prevent CVS after SAH.