The selective oxidation of propane to acrolein was performed on Ce-doped Ag0.3Mo0.5P0.3Ox catalysts. The maximal acrolein yield of 4.4% with 28.7% acrolein selectivity was obtained on Ce0.1Ag0.3Mo0.5P0.3Oy catalyst. The apparent activation energy of Ag0.3Mo0.5P0.3Ox catalysts decreased with the addition of Ce. The addition of Ce facilitated the C-H activation of propane and enhanced conversion of intermediate propene to acrolein. The reducibility and the concentration of Mo5+ improved as the Ce content increased and was closely related to acrolein selectivity and propane conversion. The role of Ce in these catalysts was proposed: there was formation of the redox cycle "Ce3+ + Mo6+ double left right arrow Ce4+ +Mo5+'' in Ce-doped Ag0.3Mo0.5P0.3Ox catalysts, leading to the modification of properties and catalytic performance of these catalysts.