The　effect　of　material　surface　morphology　on　the　periodic　subwavelength　of　nano-structures　induced　by　a　femtosecond　(fs)　laser　was　investigated　systematically　from　the　initial　surface　roughness,　the　different　scratches,　the　pre-formed　ripples,　and　the　＂layer-carving＂　technology　experiments.　The　results　of　the　comparative　experiments　indicate　that　the　initial　surface　conditions　of　the　target　surface　have　no　obvious　effects　on　the　spatial　structured　periods　(SSPs)　and　the　ripple　orientation　of　the　periodic　nano-structures　induced　by　a　fs　laser,　which　agreed　well　with　the　foretold　present　surface　two-plasmon　resonance　(STPR)　model.　Furthermore,　different　shapes　of　nano-grids　with　high　regularity　and　uniformity　were　obtained　by　fs-laser　fabrication.