Objective To observe the interference actien of Buqi Huoxue Decoction（Herbal decoction for reinforcing qi and activating blood）on the model rats with acute cerebral ischemia.Methods Sixty SD rats were randomized into 6 groups

i.e.sham operation group

model group

nimodipine group

and Buqi Huoxue Decoction groups of high

middle

and low dosages

with 10 rats in each.Except the model and sham operation groups

the others were given Buqi Huoxue Decoction through intragastric gavage for 5 days.The acute cerebral ischemia models were made on the sixth day.One hour before modeling

the last medication was applied.At the time point 6h

12h

and 24h

the blood sample was taken from the aorta abdominalis for detecting the tumor necrosis factor-α（TNF-α）.After 24h

the hemorheology test was performed.Results Compared with the model group

the whole blood viscosity including the high shear rate and low shear rate and erythrocyte aggregation index of the Nimodipine group and Buqi Huoxue Decoction groups of high and middle dosages were lowered（P<0.05 or P<0.01）

fibrinogen increased（P<0.01）.Compared with the Nimodipine group

the erythrocyte aggregation index of the Buqi Huoxue group of high dosage and the improvement of fibrinogen were both better than those of Nimodipine group（P<0.05）.Compared with the sham operation group

plasma TNF-α content in the model group started to increase at the time point of 6h and reached to the peak at 12h.Compared with the same time point in the model group

plasma TNF-α content in all treated groups was decreased

the TNF-α content of Buqi Huoxue groups of middle and low dosages at 6h and 12h was effectively decreased

while the TNF-α content of Buqi Huoxue group of high dosage was still kept at a low level at 24h（P<0.01）

and at 12h it was better than that of the Nimodipine group（P<0.05）.Conclusion Buqi Huoxue Decoction can improve the pathological changes of hemorheology and the anti-inflammation damage of the rats with acute cerebral ischemia

particularly

a better effect can be achieved with the high dose given if starting from the 12 hours after the damage.