We　studied　the　room　temperature　UV　emission　of　ZnO　films　with　different　defect　densities　which　is　fabricated　by　KrF　laser　irradiation　process.　Iris　shown　room　temperature　UV　photoluminescence　of　ZnO　film　is　composed　of　contribution　from　free-exciton　(FX)　recombination　and　its　longitudinal-optical　phonon　replica　(FX-LO)(1LO,　2LO).　With　increase　of　the　defect　density,　the　FX　emission　decreased　and　FX-LO　emission　increased　dramatically;　and　the　relative　strengths　of　FX　to　FX-LO　emission　intensities　determine　the　peak　position　and　intensity　of　UV　emission.　What　is　more,　laser　irradiation　with　moderate　energy　density　could　induce　the　crystalline　ZnO　film　with　very　flat　and　smooth　surface.　This　investigation　indicates　that　KrF　laser　irradiation　could　effectively　modulate　the　exciton　emission　and　surface　morphology,　which　is　important　for　the　application　of　high　performance　of　UV　emitting　optoelectronic　devices.　(C)　2010　Elsevier　B.V.　All　rights　reserved.