The　La2O3-MO　precursor　powder　was　prepared　by　the　Sol-gel　methods　and　two　step　reduction.　The　composition　and　micrograph　of　the　(2%-5%wt)La2O3-MO　materials　were　tested　by　the　XRD,　SEM　etc　methods.　The　results　show　that　the　rare　elements　La　exist　taking　the　form　of　La2O3　in　the　powder　and　sintering　body.　The　La2O3　particles　with　granularity　of　less　than　100　nm　disperse　uniformly　in　the　2　sintering　body.　The　thermionic　emission　current　at　zero　field　reaches　7.96　A/cm(2)　at　1　400　degrees　C.　After　the　exposure　to　the　atmosphere　the　La2O3-MO　thermionic　emission　performance　can　resume　by　re-activation　at　1　350　degrees　C