Objective    To evaluate electroencephalogram and regional cerebral blood flow (rCBF) in monitoring the establishment of a non-craniotomy model of subarachnoid hemorrhage (SAH) in rats.     Methods    The SAH model was established according to Bederson’s method. Forty-eight rats were randomly divided into control group

sham operated group and SAH group. The dynamic changes of EEG and rCBF as well as the pathological anatomy were observed in postoperative 24 h.     Results    EEG and rCBF had not diversity among three groups before operation and in the control group through the whole experiment. In the sham operated group

the amplitude of EEG decreased by (8.48±2.01)% in 5 min  and rCBF also decreased by (7.60±0.60)% in 10 min

then reverted to preoperative level. Abnormal observation was not found by pathological anatomy in the control and sham operated groups. The amplitude of EEG decreased by (77.86±3.25)% and δ wave increased in 1 min after SAH

and it at 24 h showed difference with the preoperative level. The decreased amplitude of EEG was correlated to subarachnoid hemorrhagic volume and velocity. The changes of rCBF had biphasic response

first decreased to (78.00±2.39)% of the preoperative level immediately after SAH

and increased to (89.85±5.72)% in 10 min

then decreased again to (47.68±4.72)% within 2 h and lasted for 24 h stably.     Conclusion    The dynamic changes of EEG and rCBF can be taken to judge whether SAH is successfully established and indirectly reflect the volume and velocity of subarachnoid hemorrhage.