The　film-under-gate　field　emission　arrays　(FEAs)　have　been　fabricated　on　the　glass　substrates　by　conventional　photolithography,　anodic　oxidation　and　lift-off　method.　SnO2　emitters　were　deposited　on　the　cathode　electrodes　of　under-gate　triode　by　screen　printing.　The　image　of　film-under-gate　field　emission　arrays　with　SnO2　emitters　was　measured　by　the　optical　microscopy　and　field　emission　scanning　electron　microscopy　(FESEM).　The　electric　field　distributions　and　electron　trajectories　of　film-under-gate　triode　were　simulated　in　the　same　anode　voltage　and　different　gate　voltage　by　ANSYS.　I-V　characteristics　of　film-under-gate　triode　with　SnO2　emitters　were　investigated.　It　indicated　that　the　SnO2　emitters　by　screen　printing　uniformly　distributed　on　the　surface　of　cathode　electrodes.　The　maximum　anode　current　in　this　triode　structure　could　come　to　385　μA　and　the　highest　lightness　was　approximately　270　cd/m2　as　the　gate　and　anode　voltage　was　140　V　and　2000　V,　respectively,　at　the　anode-cathode　spacing　of　1100　μm.　Moreover,　the　emission　current　fluctuation　was　less　than　5%　for　8　h.　It　showed　that　the　fabricated　device　has　a　good　stability　of　field　emission　performance　and　long　lifetime,　which　may　lead　to　practical　applications　for　field　emission　electron　source　based　on　flat　lamp　for　back　light　units　(BLUs)　in　liquid　crystal　display　(LCD).　©　2010　Elsevier　B.V.　All　rights　reserved.