Selective　laser　sintering　(SLS)　is　a　rapid　manufacturing　technology　that　builds　objects　layer　by　layer　using　a　computer　controlled　laser.　Considerable　investigations　have　been　carried　to　verify　the　process　experimentally　and　numerically.　However,　most　of　the　investigations　have　been　focused　on　producing　the　fully　dense　and　functional　components　in　high　performance,　and　less　work　has　been　done　to　the　porous　materials　or　components.　In　the　present　study,　a　3D　micro　scale　finite　element　model　has　been　established　to　simulate　the　formation　of　the　porous　structure.　A　unit　cell　with　consideration　of　the　distribution　of　powder　and　pores　are　used　to　describe　the　structure　of　the　compact　in　SLS.　And　the　effect　of　such　parameters　as　laser　power,　powder　size　as　well　as　powder　space　on　the　temperature　field　will　also　be　discussed.