ZnO　quantum　dots　(QDs)　have　been　decorated　on　graphene　deposited　on　patterned　Ag　electrodes　as　a　field　emission　cathode　by　a　solution　process.　Effects　of　ZnO　QDs　on　the　field　emission　behavior　of　graphene　are　studied　by　experiment　and　first-principles　calculations.　The　results　indicate　that　the　attachment　of　ZnO　QDs　with　a　C　atom　leads　to　the　enhancement　of　electron　emission　from　graphene,　which　is　mainly　attributed　to　the　reduction　of　the　work　function　and　ionization　potential,　and　the　increase　of　the　Fermi　level　of　graphene　after　the　decoration.　A　change　in　the　local　density　distribution　and　the　density　of　states　near　the　Fermi　level　may　also　account　for　this　behavior.　Our　study　may　help　to　develop　new　field　emission　composites　and　expand　ZnO　QDs　in　applications　for　electron　emission　devices　as　well.