The effect of post weld heat treatment on microstructures, tensile and corrosion properties of Inconel601 weld seam was investigated. The results indicated that the microstructure of weld metal consisted of coarser columnar grains with (Nb, Ti)-rich precipitations and laves phase distributed in them. Tensile and corrosion test displayed that the weld seam without any heat treatment exhibit the lowest mechanical and corrosion properties. Solution treatment at 1050°C was found to result in the considerable refinement of grain size and finally the improvement of mechanical and corrosion properties. It was also found that the specimens had the best mechanical and corrosion properties after heat treatment at 1150°C. However, with the treatment temperature increasing to 1200°C, the grain began to grow up, leading to the decrease of tensile strength and corrosion resistance.