Abstract: This paper introduces the Insulated gate bipolar transistor (IGBT) inverter for arc welding. The principle of the inverter, the structure and characteristics of IGBT and the current feedback system using LEM current transducer arc discussed. By the measurement of its efficiency and power factor and the tests of welding processes, the developed 150A IGBT inverter proves to be a kind of energy-saving portable power supply for arc welding with broad prospects.