Abstract: The extract craft conditions of flavones in Houttuynia Cordata Thunb were determined,and its antiallergic activity was studied simultaneously.And the optimal conditions were found by responds surface methodology:extract time is X1=51.66min,a volume ratio of liquid to solid is X2=49.03:1,extract temperature is X3=76.05℃,and under these conditions,the content of flavones is 9.03%.The antiallergic experimentation indicate:Houttuynia Cordata Thunb extract have a strongly inhibition to hyaluronidase,and stronger than Lithocarps Litseifolius Rehd on the inhibition to hyaluronidase,then can get dose-effect relation of Houttuynia Cordata Thunb extract,its inhibition is 35.05% on mice,at the dose of 300mg/kg can very significantly inhibit to mice’s blood capillary penatrativity increased by histamine.