The effect of boron on the performance of MoO3/CeO2-Al2O3 catalysts, which were prepared with impregnation method, was investigated. The catalysts were characterized with N-2 adsorption-desorption, XRD, H-2-TPR, and NH3-TPD, and were tested in sulfur-resistant methanation. The results indicated that the MoO3/CeO2-Al2O3 catalysts modified by boron showed higher catalytic performance in sulfur-resistant methanation. The CO conversion increased from 47% to 62% with 0.5 wt% boron content. When the content of boron was under 0.5 wt%, the results suggested there was an increase in the amorphous form of MoO3 caused by the generation of weak and intermediate acid sites, which had weakened the interaction between the active components and supports. While, the catalyst added 2.0 wt% boron showed the strong acid sites and the largest crystalline size resulting in the uneven distribution of ceria. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.