In the process of Gas Metal Arc Welding, achieving a favorable geometry meeting all requirements of the manufacturer is considered important. Therefore, for addressing these issues automated systems and modeling and optimization of the process are necessary. In the present study, empirical studies were carried out on CK45 steel considering four parameters including voltage, wire feed speed, welding speed, and welding nozzle angle as parameters affecting the welding geometry. Weld height and width were considered as the output parameter. Furthermore, for modeling the process, the surface response method was us, and finally, the process parameters were optimized using the particle pool method. The results obtained from the modeling have declared the voltage parameters of 17 wire feeding speeds of 244 welding speed of 160 and nozzle angle of 105 degrees as optimal. Examining the data predicted by the model and compared with the available experimental data, it is shown that by increasing both the wire speed and voltage and also minimizing the table speed, the width of the weld bead increases while increasing the voltage and wire speed and reducing the table speed, make the height of the bead to decrease. Hence, not only increasing the angle of the nozzle and wire-speed but also decreasing the voltage and table speed results in a decrease in the amount of dilution.