Abstract: Licorice is used as an importan t traditional herbal medicine. The flavonoids inlicorice is one kind-of components having higher biological effects ,among them ’liquiritigenin(VI)and isoliquiritigenin ( Ⅳ )have special activities in the treatment of AIDS.In this article l differentways to synthesize the two compounds ,including synthesis of isoliquiritigenin(Ⅳ)by Fries-reaction,Aldol condensation under acid or base catalyst l and conversion to liquiritigenin(Ⅵ )fromisoliquiritigenin(Ⅳ)were studied and a better procedure was obtained.