A　series　of　Ni-Cu-Mn-K/Al2O3　multi-metal　component　catalysts　with　different　K2CO3　loading　used　for　Water-Gas　Shift　Reaction　were　prepared　by　impregnation　method.　The　effect　of　K　2CO3　content　on　the　structure　and　property　of　the　catalysts　was　studied　by　N2　physical　adsorption,　XRD,　H　2-TPR　and　CO-TPD　techniques.　The　results　show　that　the　addition　of　a　certain　K2CO3　could　result　in　increase　of　the　reduction　temperature,　the　electron-density　of　the　activity　compositions　and　the　ability　of　electron　donation　for　activating　CO　in　the　catalysts,　thus　enhancing　their　catalytic　activity.　However,　the　excess　K2CO3　would　lead　to　the　decrease　of　surface　area　and　pore　volume,　and　lead　to　the　increase　of　CO　adsorption　ability,　thus　resulting　in　the　decrease　of　catalytic　activity.　After　Ni-Cu-Mn-K/Al2O3　catalyst　with　K2CO3　content　of　7.5%　calcined　at　530　°C　for　15　h,　its　CO　conversion　is　62.29%　for　water　gas　shift　reaction　at　350　°C.