Abstract: The optimum conditions of ultrasonic wave-assisted extraction technology for litchi polysaccharides were determined with the single factor and the RSA response surface method. The results showed that the optimum conditions were : dried litchi pulp was used as raw materials, water as the extracting agent, ultrasonic power 72W, extraction time 32min, and the liquid-solid ratio 12:1. Under these optimum extraction conditions, the extraction rate of the crude litchi polysaccharides reached 18.94%.