In　this　paper,　the　recent　progresses　on　nanosized-scandia-doped　impregnated　(SDI)　dispenser　cathodes　made　in　this　research　group　are　reviewed.　Spray-drying　process,　a　new　method　for　nonosized-scandia-doped　tungsten　powder　preparation,　has　been　developed.　Compared　with　the　formerly　used　sol-gel　technique,　the　new　method　results　in　more　controls　over　the　tungsten　grain　size　and　morphology.　Similar　emission　level　can　be　reached　for　the　cathodes　made　from　this　kind　of　powder　to　that　of　made　by　sol-gel　process.　Continuously　pulsed　emission　life　test　at　about　50　A/cm2　has　been　carried　out　in　a　Pierce-gun　open　structure　tube　at　e　beam　inc.,　USA　and　has　been　steady　for　nearly　the　entire　period　of　1000　hours.　A　knee　temperature　as　low　as　900　°CB-Mo　for　initial　current　density　of　58　A/cm2　was　estimated　from　the　Miram　curve.　DC　emission　has　been　evaluated　in　a　closely-spaced　diode　system　with　water-cooled　copper　anode.　Over　60　A/cm2　space　charge　limited　(SCL)　DC　current　density　was　repeatedly　measured　at　950　°CB-Mo.　Below　this　level　the　DC　and　pulsed　emission　are　agree　well.　In　DC　life　test　at　950　°CB-Mo,　an　initial　current　density　of　20　A/cm2　rose　gradually　to　about　30　A/cm2　during　first　several　hundred　hours　then　remained　stably　for　more　than　2000　hours.　The　increase　in　emission　capability　has　also　be　verified　by　a　comparison　of　I/V　characters　at　beginning　and　1000　hours　of　the　life　test.　The　improvement　of　emission　performance　for　SDI　cathodes　has　been　correlated　to　the　surface　composition　changes　during　life　which　was　performed　by　in　situ　surface　analysis.　©　2014　IEEE.