Abstract: This paper focuses on the technological test results and their analyses with arc welding MOSFET inverter.A large number of technological tests have been carried out on stainless steel,silicon steel sheet and copper by using GTAW process.The results,show that this new type of high efficiency,compact electronic arc welding power source has excellent technological properties including easiness for arc ignitiation,good arc stability,nice weld appearance,and low noise.Furthermore,the MOSFET inverter has great advantages over the transistor inverter and thyristor inverter for arc welding on weight reducing,material saving and manufacture process simplifying etc.Therefore it reveals a broad prospective development for its extensive and practical applications.