Objective:To explore the mechanism of Qiaoqing Qingfeiji to relieving asthma of asthma model by studying the effect of Qiaoqin Qingfeiji on relieving asthma and the relation between it and the content of platelet-activating factor（PAF）

white blood cell（WBC）

eosinophils（EOS） and endothelin（ET） of asthma model.Method:Rats were divided into 6 groups:normal control group

asthmatic model group

Qiaoqin Qingfeiji with hight

meddle

and low dosage groups

and dexamethasone group

and aminophylline group.Asthmatic model was established by sensitizing and challenging rats with ovalbumin（OVA）.Except the normal control group

other groups were injected 10% OVA into abdominal cavities in the 1th day and the 8th day.2 weeks later followed by aerosolized 1% OVA once a day challenge to prepare the asthma models for 2 weeks.The drugs for every group were given intragastrically from the second day of rat sensitization for 4 weeks（the dexamethasone was given from the 1th day）.The effect of medicine on the asthma degree

asthma latency period and the content of PAF

WBC and EOS in serum

and ET in bronchoalveolar lavage fluid（BALF） of asthma model were observed.Result:Qiaoqin Qingfeiji can obviously improved the asthma degree

and extend asthma latency period（P<0.05）

and obviously decrease the content of PAF

WBC and ET（P<0.05-0.01）.Conclusion:Qiaoqin Qingfeiji can effectively recover from status asthmaticus

reduce the severity of asthma attacks.It is relate to reduce the content of PAF and WBC in serum

and ET in BALF of asthma model.