In　this　paper,　a　periodic　n-species　Gilpin-Ayala　competition　system　with　impulses　is　studied.　By　constructing　a　suitable　Lyapunov　function　and　using　the　comparison　theorem　of　impulsive　differential　equations,　a　set　of　sufficient　conditions　which　guarantee　that　some　species　in　the　system　are　permanent　and　globally　attractive　while　the　remaining　species　are　driven　to　extinction　are　obtained.　Our　results　show　that　the　dynamic　behaviors　of　the　system　we　considered　are　quite　different　from　the　corresponding　system　without　impulses.　(C)　2009　Elsevier　Ltd.　All　rights　reserved