Rare　earth　element　(La,　Y,　and　Ce)　modified　MgAl-hydrotalcites　of　MgAlM　were　synthesized　from　coprecipitation　and　calcination,　and　further　loaded　with　CoMo　active　species　to　give　CoMo/MgAlM　catalysts.　X-ray　powder　diffraction,　inductively　coupled　plasma,　and　N(2　)adsorption　isotherms　indicate　that　MgAlM　possess　large　BET　surface　areas　(58-91　m(2)/g),　and　rare　earth　elements　were　successfully　introduced　into　samples.　CO2-TPD　(temperature-programmed　desorption),　NH3-TPD,　H-2-TPR　(temperature-programmed　reduction),　H2S-TPS　(temperature-programmed　sulfidation),　and　Raman　spectra　indicate　the　presence　of　unique　interactions　between　rare　earth　elements　and　Mo　active　species,　which　strongly　affect　the　reduction　and　sulfidation　behaviors　of　these　catalysts.　High　resolution　transmission　electron　microscopy　(HRTEM)　and　X-ray　photoelectron　spectroscopy　(XPS)　analysis　suggest　that　the　addition　of　rare　earth　elements　decreases　the　slab　length　and　stacking　numbers　of　MoS(2)and　promotes　the　sulfidation　degree　of　Mo　oxides.　The　above　characteristics　make　CoMo/MgAlM　act　as　highly　active　catalysts　for　the　water　gas　shift　reaction　(WGSR).　This　work　develops　a　facile　and　cost-effective　method　for　rational　design　of　efficient　catalysts　for　WGSR　in　industrial　processes.