Sheets　of　a　new　Al-Zn-Mg-Cu　alloy　with　T6　temper　were　welded　using　TIC　and　laser　welding　method.　Microstructure　characteristics　and　mechanical　properties　of　joints　were　contrastively　analyzed.　Results　show　that　the　width　of　the　fusion　zone　(FZ)　and　heat　affected　zone　(HAZ)　in　laser　joint　is　obviously　smaller.　The　FZs　in　TIC　and　laser　joints　are　both　made　up　of　dendritic　equiaxed　grains　and　lots　of　coarse　particles,　the　mean　grain　size　is　33.9　mu　m　and　6.1　mu　m　respectively,　and　the　coarse　particles　are　identified　as　the　T　(AIZnMgCu)　phase.　The　two　factors　of　grain　size　and　alloying　elements　distribution　are　combined　to　result　in　almost　the　same　microhardness　of　the　two　FZs.　Moreover,　the　grain　morphology,　grain　size　and　degree　of　recrystallization　of　the　two　HAZs　are　almost　the　same　with　base　metal　(BM).　Due　to　the　higher　heating　and　cooling　rate　of　welding　thermal　cycles　in　HAZ　of　laser　joint,　the　microhardness　is　obviously　higher.　The　minimum　microhardness　of　the　two　joints　is　obtained　in　FZ　where　the　fractures　always　occur　in　the　tensile　tests,　the　ultimate　tensile　strength　of　TIG　and　laser　joints　is　436.2　MPa　and　471.1　MPa,　the　elongation　of　them　is　about　7.5%　and　5.1%　respectively.　(C)　2015　Elsevier　Ltd.　All　rights　reserved.