The　morphology　and　crystalline　phase　characteristics　of　amorphous　Ge2Sb2Te5　films　irradiated　by　a　picosecond　laser　were　investigated　by　3D　surface　profiler,　atomic　force　microscopy　(AFM)　and　transmission　electron　microscopy　(TEM)　integrated　with　selected　area　electron　diffraction　(SAED).　The　laser　irradiated　spot　was　divided　into　strong　ablation　area,　gentle　ablation　area,　melting　area　and　irradiation　area.　By　theoretical　calculation,　the　ablation　and　melting　thresholds　were　determined　to　be　173.05　mJ　cm(-2)　and　99.19　mJ　cm(-2)　respectively.　Meantime,　the　local　fine　morphologies　of　the　ablation　and　melting　areas　were　shown　and　analyzed.　We　also　studied　the　irradiation　area　which　was　made　up　by　the　non-phase-change　area　and　phase-change　area.　In　the　phase-change　area,　crystalline　phase　was　determined　to　be　face-centered　cubic　structure　and　crystalline　phase　characteristics　for　films　with　different　thicknesses　were　discussed.　(C)　2013　Elsevier　B.V.　All　rights　reserved.