This paper describes the proces of electric arc welding in the zone of protective gas, with an emphasis on transmitting metal dropelts via a short ciruit.Parameters of the welding proces and of an electric arc are described, and a mathemacal model for the MIG system is sugessted. Model simulation is completed used Matlab/Simulink package. The proces is simulated using real parameters in order for the output values of the process to corespond to real values obtained by the means of mesasurement.