In　this　work,　we　investigate　effects　of　scanning　speed　(800　mm　s(-1),　900　mm　s(-1),　1083　mm　s(-1))　on　in　vitro　biocompatibility　of　316L　stainless　steel　(SS)　parts　elaborated　by　selective　laser　melting　(SLM).　Cytotoxicity　assay　and　hemolytic　test　are　adopted　to　assess　the　in　vitro　biocompatibility　of　316L　SS　parts.　The　experimental　results　show　that　the　scanning　speed　has　strong　effects　on　the　in　vitro　cytotoxicity　of　316L　SS　parts　and　no　significant　effect　on　the　hemolysis.　In　order　to　investigate　the　mechanism　of　effects　of　scanning　speed　on　in　vitro　biocompatibility,　microstructures　of　316L　SS　parts　via　SLM　are　obtained　by　scanning　electron　microscopy　(SEM).　The　finer　grain　and　less　defects　lead　to　better　biocompatibility,　due　to　the　increase　of　corrosion　resistance　and　decrease　of　toxicity　ions　release.　In　cases　of　900　and　1083　mm　s(-1),　finer　microstructures　can　be　observed　and　the　minimum　manufacturing　defects　are　formed　on　316L　SS　parts　under　900　mm　s(-1)　scanning　speed.　The　results　indicate　that　by　changing　the　scanning　speed,　the　microstructures,　in　terms　of　the　quality　of　grain　and　the　mount　of　defects,　can　be　adjusted;　as　a　result,　controllable　biocompatibility　of　316L　SS　parts　via　SLM　can　be　achieved.