According　to　the　structure　form,　the　geometry　character　of　cross　section,　and　stress　state　of　T-joint,　a　mechanical　sample　was　designed　for　predigesting　assembled　stress　of　fillet　weld　to　a　single　one.　The　tensile　test　and　fatigue　test　were　carried　out　and　the　test　data　were　analyzed.　The　results　show　that　the　most　basic　mechanical　performance　of　fillet　weld　of　T-joint　is　obtained　by　adopting　the　designed　sample.　The　theory　results　are　accordant　with　the　practice　load　strain　curve.　It　has　significant　to　analyze　mechanical　performance　of　T-joint　by　the　obtained　test　data.