In　this　paper,　the　effect　of　laser　wavelength　on　the　thermal　behavior　of　amorphous　Ge2Sb2Te5　(a-GST)　films　induced　by　a　frequency-tripled　picosecond　laser　was　carried　out　using　3D　surface　profile,　SEM,　TEM　and　Raman　measurement.　Melting　thresholds　of　a-GST　films　with　different　wavelengths　of　355　nm　(3.5　mJ/cm(2)),　532　nm　(28　mJ/cm(2))　and　1064　nm　(22.3　mJ/cm(2))　were　obtained,　respectively.　It　showed　that　with　the　increase　of　wavelength　from　355　to　532　and　1064　nm,　pit　morphologies　and　crystallization　degree　didn＇t　follow　a　monotonous　relation,　which　were　mainly　affected　by　melting　threshold,　optical　penetration　depth　as　well　as　photon　energy.　TEM　images　demonstrated　that　532　nm　laser-treated　samples　got　more　complete　crystallization　than　those　355　nm　laser　treated.　Besides,　for　the　remarkable　discrepancy　in　optical　penetration　depth　among　the　three　laser　wavelengths,　the　crystallization　process　of　a-GST　at　355　and　532　nm　wavelengths　performed　with　a　surficial　heating　mode,　different　from　that　at　1064　nm　wavelength　with　a　body　heating　mode.　The　present　study　paves　the　way　to　achieve　the　big-data　storage　using　different　wavelengths.