The factors that effect the extraction rate of corn cob xylan was studied. They include: pretreatment methods, time, temperature, pH, concentration of NaOH and so on. The optimum process was as follow: pretreat with 0.1%H2SO4, time 2h, ratio of solid to liquid 1:20, temperature 70 ℃, adjust pH to 5, add twice volume 95% alcohol, precipitated for 1hour, NaOH concentration 10%. By using it, the extraction rate was 28.1% .The effect of ultrasonic wave on extraction rate of corn cob xylan was studied. Through o...