Objective To observe the expression of MMP-9-mRNA and PA-mRNA when it's intervened by traditional herbal medicines NTE（extract of NaoTaiFang，contain HuangQi， Chuan Xiong， Di Long， Jiang Can） in cerebral ischemia and observe effects of cerebral water content in brain. Methods The rats were randomly allotted 5 groups as following： sham operation group，model group， low dose group of NTE（3 g/kg）， medial dose group of NTE（9g/kg）， large dose group of NTE（27 g/kg）. Three days before operation， the corresponding therapy was treated by intragastric administration once every day， After operation， the rats were treated with previous method. Togive materials 24 hours after operation， the water content of brain was detected. MMP-9-mRNA and PA-mRNA in necrotic region were measured by RT-PCR with marketable kit. Results Compared with Model group， the different dose groups of NTE display a lower water content（P＜0.05）； Big dose group of NTE show lower lever of MMP-9-mRNA and PA-mRNA compared with Model group（P<0.05）. Conclusion NTE can reduce the expression of MMP-9-mRNA and PA-mRNA in cerebral ischemia，then reduce the MMP-9 and PA to protect the BBB， and alleviate cerebral edema.