Bioethanol fermentation residues of reed- and corn stover-pretreated with liquid hot water were liquefied using aluminum chloride as the main catalyst in the presence of ethanol. Effects of various liquefaction conditions on the liquefied residue content were investigated. Compositions of the liquefaction products were analyzed after being separated into three fractions: water-insoluble fraction, chloroform extract, and remaining product after chloroform extraction. The major component of water-insoluble fraction was lignin. After chloroform extraction, the extracted fractions were mainly esters, phenols, hydrocarbons, and their derivatives, and the residues mainly contained some acids such as levulinic acid, acetic acid, propionic acid and formic acid. It was found that aluminum chloride promoted the liquefaction process significantly in the presence of ethanol, and breakdown of some linkage bonds in lignin of the fermentation residues, such as methoxy group, C-C and C-O, was occurred in the liquefaction process. (C) 2014 Elsevier B.V. All rights reserved.