Selective　laser　melting　(SLM)　is　one　of　the　important　additive　manufacturing　technologies　which　can　produce　high　quality　parts　with　complex　geometry.　The　main　objective　of　current　study　is　to　investigate　laser　welding　of　2　mm　thick　AlSi10Mg　parts　fabricated　by　SLM,　and　to　emphasis　on　the　weld　shape,　microstructure,　pore　distribution　and　hardness　of　the　welded　joints.　The　results　show　that　the　cross　section　of　the　welds　is　multi-pass　welding　appearance,　and　the　cross-sectional　area　of　the　welded　joints　increases　from　1.58　mm(2)　to　3.66　mm(2)　with　increasing　heat　input　from　51　J/mm　to　135　J/mm.　The　increased　heat　input　causes　the　grain　size　of　the　welds　to　increase　from　1.1　mu　m　to　2.5　mu　m.　Circular　pores　are　observed　under　different　heat　inputs,　and　the　maximum　pore　diameter　increases　from　92.0　mu　m　to　155.4　mu　m　with　the　increase　of　heat　input.　The　hardness　of　the　weld　zone　is　lower　than　that　of　the　base　metal,　whereas　the　increase　in　heat　input　causes　the　average　hardness　to　decrease　from　86.7　HV　to　77.8　HV.　These　preliminary　results　demonstrate　that　it　is　the　feasible　to　joining　SLM　AlSi10Mg　parts　by　using　laser　welding　process.