Abstract: Effects of Ti and Zr additions in filler wires on the microstructure and properties of metal inert gas (MIG) welding of 2219 Al-Cu alloy were investigated by means of mechanical property tests,OM and SEM.The results show that refinement effect of Ti and Zr was compatible.The coarse and oriented columnar grains reformed to fine equiaxed grains with the content increase of Ti and Zr in filler wires,which improved the morphology and distribution of α(Al)-CuAl2 eutectic along grain boundaries and interdendritic.So the microhardness,tensile strength and elongation of the weld joint was increased greatly.