After hydrothermal pretreatment of corn stover, solid fraction and hydrolysate were collected separately. To find out the appropriate process for ethanol production from corn stover, ethanol production was evaluated from dried solid fraction and the hydrolysate employed as liquid fraction by baker’ yeast. The effects of different pH value and detoxification on ethanol production were investigated. Firstly, prehydrolysis was performed at 50℃ for 24h. When 100% hydrolysate was added, ethanol content of 0.31g/L (9.48% of theoretical ethanol yield) was obtained based on the cellulose available in the pretreated corn stover due to the existence of acetic acid and furans which are important inhibitors of the fermentation to microorganisms. After prehydrolysis, the initial pH value was adjusted to 5.5, 6.0 and 6.5, respectively. The best value obtained was ethanol content of 10.67g/L with addition of 100% hydrolysate at pH value of 5.5. The hydrolysate was overlimed, then prehydrolysized for 24h at 50℃. After prehydrolysis, the initial pH value was adjusted again to 5.5. Ethanol content of 10.96g/L (57.9% of theoretical ethanol yield) was obtained. Ethanol yield increased almost 6 times compared to that at pH value of 4.8.