Abstract:With lentinan as the raw material，obtained polysaccharides from lentinan through the ultrasonicassisted extraction process.It had been researched that solid-liquid rate，ultrasonic power，the extraction temperature and ultrasonic time had effect on extraction rate of polysaccharides from lentinan by means single factor and orthogonal experiment method，which use extraction rate as the evaluation index.The results showed that ultrasonic-assisted extraction conditions of polysaccharides from lentinan had the best effect，and the optimal ultrasonic-assisted extraction conditions were solid-liquid rate 1 ∶50（g/mL），ultrasonic power 300 W，the extraction temperature 50℃，and ultrasonic time 40 min.After three parallel experiments under the condition of the optimal extraction process，and the yield of letinan was 11.73%.It suggested that the extraction process was reasonable，the results were stable and feasible.