Objective To explore the chiaical value of cerebral perfusion reduction after subarachnoid hemorrhage(SAH)by multi spiral CT perfusion in rabbits.Methods 32 male Japanese big-ear rabbits of clean level were randomly divided into 2 groups:Group A(n =8),the normal group,were to obtain normal MS-CTP values of rabbit cerebrums;Group B(n =24),the SAH group was made into two-hemorrhage animal models,checked on seven day by multi spiral CT perfusion.The source data was transmitted to the post-processing workstation ADW 4.2.Perfusion parameters maps(CBF)of both sides of frontal,parietal and basal ganglia were got by computing.Each rabbit was killed immediately after scanning,and the spider blood was observed.Results The average CBF value of the two groups:The difference was not statistically significant at the frontal(t =1.740,P =0.092)and parietal(t =1.868,P =0.072); The average values of CBF were significantly decreased at the basal ganglia(t =2.481,P =0.019).Group B showed the distribution of blood clot in the basal cistern,but there was no blood clot at the frontal and parietal.Conclusion The monitor perfusion changes of rabbit brain after SAH could be detected by MS-CTP,and the lower of regional cerebral perfusion had a relationship with the distribution with the blood clot,and it could instruct the early diagnosis of cerebral perfusion,and the clinical benefit to early intervention treatment.