Micro-fluidic　channel　was　fabricated　on　a　PMMA　sheet　(thickness　of　1.5　mm)　using　248　nm　excimer　laser　direct-writing　technique.　The　influence　of　excimer　laser　fluence　on　the　micromachining　quality　(channel＇s　depth　and　surface　roughness)　was　analyzed.　Higher　laser　fluence　results　in　the　augmentation　of　channel＇s　depth　and　surface　roughness.　The　excimer　laser　polishing　processing　is　favorable　for　the　improvement　of　surface　roughness.　However,　over-abundant　polishing　will　generate　tenuous　stripe　on　the　channel＇s　edge　and　worsen　the　surface　roughness.