In　this　study,　the　SUS3011　austenitic　stainless　steel　plates　were　welded　under　different　protective　conditions　with　different　percentages　of　N-2/Ar.　The　welded　joints,　that　were　produced　using　fiber　laser　welding　and　CO2　laser　welding,　showed　good　shape　and　there　were　no　significant　differences　in　microstructure　under　different　protective　conditions.　The　welds　consisted　of　gamma-austenite　and　small　amounts　of　delta-ferrite,　and　the　welded　joints　were　of　approximately　equal　to　the　base　metal　in　terms　of　their　tensile　strength　and　micro-hardness.　The　nitrogen　that　was　absorbed　by　the　molten　pool　mainly　was　concentrated　around　the　surface　of　the　weld　and　was　present　in　the　form　Cr2N,　CrN　and　FeN.　With　an　increase　of　the　N-2　percentages　in　the　protective　gas,　the　anti-corrosion　performance　of　the　welds　was　improved.　Compared　with　the　fiber　laser　welding,　the　weld　after　CO2　laser　welding　had　a　slightly　higher　nitrogen　content　and　better　corrosion　resistance.