The addition of hydrogen in shielding gas has been found to contribute to increasing the productivity of gas tungsten arc (GTA) welding compared to the processes using argon-nitrogen shielding gas. In this report, the GTA welding joints of AISI 304 stainless steel with Ar-N2 and Ar-N2-H2 addition were fabricated. The microstructure and pitting corrosion resistance were studied in this work. The corrosion characterisation of welds metal was investigated by a potentiodynamic method in NaCl solution. It was found that H2 addition also had effects on delta-ferrite microstructures and corrosion behaviour. Increasing hydrogen in argon-nitrogen shielding gas increased the delta-ferrite content and improved pitting corrosion resistance.