Water-gas　shift　reaction　was　carried　out　over　a　series　of　CuO/CeO2　catalysts　doped　with　trivalent　rare　earth　oxide　(RE2O3,　RE　=　Y,　La,　Nd　and　Sm),　prepared　via　co-precipitation　method.　The　effect　of　the　dopants　on　the　structure　and　catalytic　properties　of　CuO/CeO2　catalysts　was　investigated　with　the　aid　of　X-ray　diffraction　(XRD),　Raman　spectra,　N-2　physisorption,　H-2-TPR　and　selective　N2O　chemisorption　characterizations.　The　results　reveal　the　beneficial　role　of　La2O3　and　Nd2O3　doping　in　increasing　the　WGS　catalytic　activities　and　stabilities　of　CuO/CeO2　catalysts,　while　the　addition　of　Y2O3　and　Sm2O3　leads　to　the　negative　effect.　Correlating　to　the　characteristic　results,　it　is　found　that　the　performance　of　CuO/CeO2-RE2O3　catalysts　strongly　depends　on　their　surface　copper　dispersion,　microstrain　value　and　the　amount　of　oxygen　vacancies　generated　in　ceria　lattice.　Besides,　enough　evidences　suggest　that,　the　most　effective　active　site　for　WGS　reaction　is　the　moderate　copper　oxide　(crystalline)　interacted　with　surface　oxygen　vacancies　of　ceria　in　the　CuO-CeO2　system.　(C)　2009　Professor　T.　Nejat　Veziroglu.　Published　by　Elsevier　Ltd.　All　rights　reserved.