Abstract: Liquefaction of corn stalk was studied using a high-pressure batch autoclave under the subcritical and supercritical ethanol-water condition. The results indicated that the conversion and extraction of the liquefied products increased at first and then declined with the increasing concentration of ethanol and had a maximum between 0.09 and 0.35. Under the experimental conditions used for this study, the maximum conversion yield and extraction yield were 88.52% and 52.52%, respectively, at 0.21 mol fraction of ethanol concentration. Extracted with organic solvent, the product of liquefaction was separated into organic dissolved, oil dissolved and residue. The results showed that the oil dissolved increased and the organic dissolved reduced with the increasing concentration of ethanol.