Hydrothermal liquefaction of corn stalk under CO atmosphere with three commercial heterogeneous catalysts was performed in a high pressure autoclave. The structure and reducibility of the catalysts were studied by X-ray diffraction and differential thermal gravity under H-2 atmosphere. The results indicated that the catalysts greatly increased the conversion of cornstalk yield and heating value of liquid product. The activity order of the catalysts is as follows: JT203 > JT201 > JB-1, which is consistent with the high surface area and low reduction temperature of JT203. The catalysts might favor a hydrothermal liquefaction process through the active H produced by water-gas shift reaction.