Abstract: To cure 25children bronchial asthma with Ginkgo biloba extract and hormo ne repectively.The level of blood platelet activating f actor(PAF)before and after the treatment on bro nchial asthma children with Ginkgo biloba extract was examined in a biologicalway.To o bserve the change of clinical symptoms and compare the change of bl ood PAF level between before and afte r hormone teratment.The results werethat:the children PAF l evels of the two treatments did not exist remarkable difference.(t =0.997,p >0.05),andthe time of asthma improvement was similar.Perhaps the Ginkgobilob a extract was a kind of new drug to prevent and tr eat on bronchial asthma.

Key words: asthma, children, Ginkgo biloba extract, blood platelet activating factor