The　Al-Mg-Mn-Zr-Er　alloy　sheets　with　a　thickness　of　4　mm　were　welded　by　TIG　welding,　the　microstructures　and　mechanical　properties　of　Al-Mg-Mn-Zr-Er　alloy　weld　joints　filled　with　Phi　1.6　mm　Al-Mg-Mn-Zr　and　Al-Mg-Mn-Zr-Er　welding　wires　were　studied　by　optical　microscopy,　scanning　electron　microscopy,　transmission　electron　microscopy,　hardness　testing　and　tensile　mechanical　properties　testing.　The　result　showed　that,　the　tensile　strength　increased　by　57　MPa　and　the　coefficient　of　weld　joint　reached　0.8　when　Al-Mg-Mn-Zr-Er　welding　wire　was　used　as　filling　material.　The　tensile　strength　and　elongation　of　weld　joint　filled　with　Al-Mg-Mn-Zr-Er　welding　wire　were　19%　and　85%　higher　those　that　of　filled　with　Al-Mg-Mn-Zr　welding　wire　respectively,　which　resulted　from　grain　refinement　strengthening　and　dispersion　strengthening　of　Al3Er.