Abstarct: The aim of this thesis is to design a fuzzy Control of Arc Welding Process in Protective Gas environment. The novel of this thesis is to increase using of this kind of welding in both manual and robotic forms in Industrial Production. Here the control of arc welding process in protective gas environment in manual way is being presented. A new perspective use of fuzzy control in industrial processes for increasing quality level of welding and easiness of this operation by the welder is presented. The quality of welding is highly affected by the unpragmatism, which one of the important ones is hand flutter of the welder. Therefore unpragmatism in fuzzy controllers has no special effect in arc welding process control. Since in fuzzy control there is no need to know the mathematical models and process imposed stimulations. This characteristic is one of the main characteristics of these controllers. In control system the measurement of variant of length of arc is being considered. In addition the source of power is used on the basis of INVERTER with use of modulation technique of width of pulse for voltage production in welding machine. Simulation in MATLAB environment with industrial control of industrial electrical ac/dc exchanger has been performed. This thesis is aimed use of fuzzy control to fix the length of arc and consequently amelioration of welding quality in industrial arc welding process. The design and simulation levels of which are submitted. In simulation, considering a partly operational situation in a manual welding, especially the dynamic presence of source of power in welding machine an appropriate control has been done. To indicate the results of simulation of appropriate operation of fuzzy control system in fix of length of arc.