Xylitol was made from bagasse by ultrasonic pretreatment and fermentation.The effects of ultrasonic power,initial pH value and time of pretreatment and liquid-solid ratio on xylitol yield were discussed.The pretreatment process was optimized and analyzed by response surface methodology,and quadratic regression model was established.The results showed that ultrasonic pretreatment could promote bagasse degradation and increase xylitol yield.The xylitol yield was increased when pretreatment ultrasonic power was 450W,pretreatment initial pH value was 3.9,liqui...