A series of Mo-based catalysts supported on Ce1-x LaxO2-delta solid solution were prepared and performed in sulfur-resistant methanation. Characterization results suggested the formation of Ce1-xLaxO2-delta solid solution with a cubic fluorite structure. The correlation between the surface concentration of Ce3+ and oxygen mobility was well revealed. The higher oxygen storage capacity induced by La dopant enhanced the reducibility of the MoO3/Ce1-xLaxO2-delta during the sulfidation. Meanwhile, the presence of oxygen vacancy induced by Ce-3(+) prompted the sulfidation of Mo species, resulting in a higher dispersion of MoS2. The coupling between the CO hydrogenation and water-gas-shift (WGS) reaction is important for the sulfur-resistant methanation. The apparent methanation rate is easily determined by CO hydrogenation, and WGS reaction could provide more H-2 for the CO hydrogenation. MoO3/Ce0.8La0.2O2-delta catalyst exhibited the highest activity in a broad temperature regime of 450-550 degrees C due to its high MoS2 dispersion and surface concentration of Ce3+.