[Objective] To study the optimum ultrasonic extraction conditions of Lushan Yunwu Tea. [Method] Effects of ultrasonic time,the ratio of material to liquid,the concentration of ethanol on extraction rate of tea polyphenols from Lushan Yunwu Tea were investigated. On the basis of single-factor test,orthogonal test L9( 33) was designed. [Result]The optimal extraction conditions are as following: ethanol 70%,time20 min,solid-liquid ratio 1∶ 6 g / ml. Under these conditions,the extraction rate of tea polyphenols...