Aluminum　nitride　(AlN)　thin　films　were　prepared　by　pulsed　laser　deposition　(PLD)　at　different　substrate-target　distance　and　substrate　temperature.　The　field　emission　(FE)　measurement　showed　that　the　FE　current　increases　firstly　and　then　decreases　with　increasing　the　substrate-target　distance　or　substrate　temperature.　The　films　with　the　best　FE　properties　appear　at　the　substrate-target　distance　5.5　cm　or　substrate　temperature　is　850　degrees　C.　The　substrate-target　distance　and　substrate　temperature　determine　the　mobility　of　target　particles　on　the　substrate,　therefore　influence　the　surface　morphology　and　microstructure,　such　as　defects　and　compactness　and　so　on,　then　effect　greatly　the　FE　properties.　It　suggests　that　for　AlN　films　prepared　by　PLD,　altering　the　process　parameters　properly　is　needed　for　modulating　the　kinetic　energy　of　target　particles　on　the　substrate　to　get　surface　morphology　and　microstructure　which　is　suitable　for　better　FE.