Abstract: The polysaccharides from red flesh apple was extracted by ultrasonic assisted method using Xinjiang red flesh apple as raw materials. Firstly,the effects of the four main factors( time of operation,liquid ratio,ultrasonic power and temperature) on the yield of polysaccharides in red flesh apple was discussed through single- factor experiments. The extraction technological condition of polysaccharides from red flesh apple was optimized with response surface method after single- factor test.The results showed that the optimal parameter was as follows: the extraction temperature was 65 ℃,time was 71 min,the ultrasonic power was 450 W and liquid- solid ratio was45∶ 1( m L / g). Under this condition,the yield of polysaccharide in red flesh apple with ultrasonic extraction was the best of 4.53%,and it was close to the theoretical prediction of 4.65%. The mathematical model obtained in this experiment could accurately predict the yield of polysaccharide in red flesh apple. This results will provide a experimental basis to develop the resources of wild red flesh apple in Xinjiang.