In　this　paper,　the　crystal　morphology　and　grain　size　evolution　of　Ge-Sb-Te　(GST)　irradiated　by　multi-pulsed　picosecond　(ps)　laser　were　characterized　by　transmission　electron　microscopy　and　selected　area　electron　diffraction.　Morphologies　induced　by　multi-pulsed　laser　were　radially　quasiperiodic　structures,　and　the　crystallization　area　induced　by　the　first　laser　pulse　acted　as　the　periodic　repeated　unit.　Single　laser　pulse　irradiation　produced　three　different　conterminal　annular　crystallization　zones,　and　their　formation　mechanisms　were　discussed.　GST　films　accumulated　thermal　and　structural　change　induced　by　per　laser　pulse,　reducing　crystallization　threshold　and　extending　crystallization　fluence　range.　Sequentially,　every　subsequent　laser　pulse　created　a　new　crystallization　area,　and　then　accumulated　to　be　a　pulse　number　dependence　radially　quasiperiodic　structure.　Meanwhile,　the　laser　pulse　train　dramatically　refined　grains.　The　grain　boundaries　are　presented　as　an　alternating-layered　structure　or　atomic　ordering　domain.　The　present　study　revealed　microstructure　evolution　of　intermediate　states　for　multi-level　storage　and　realized　multi-phase　changes　and　is　critical　to　enhance　storage　density.