The　microstructure　and　properties　of　the　joint　were　studied,　based　on　the　trial　of　twin　spot　laser　welding　of　2　mm　thick　1420　aluminium-lithium　alloy.　The　characteristics　of　microstructure,　micro-hardness,　room-temperature　tensile　strength　and　fractography　of　both　twin　spot　and　single　spot　laser　welded　joints　were　compared.　The　results　indicate　that　the　microstructures　of　the　joints　by　twin　spot　and　single　spot　laser　welding　are　similar.　Equiaxed　grains,　columnar　crystals,　and　equiaxed　dendrite　crystals　can　be　found　from　fusion　zone　to　the　weld　center　in　the　twin　spot　welded　joint,　which　are　finer　than　that　of　single　spot　welded　joint.　The　microhardness　of　twin　spot　laser　welded　joint　is　higher　than　that　of　single　spot　laser　welded　joint,　but　lower　than　that　of　base　metal.　Meanwhile,　the　tensile　properties　of　twin　spot　laser　welded　joint　is　decreased　to　86%　of　that　of　base　metal,　but　a　little　higher　than　that　of　single　spot　laser　welded　joint.