The most important pathogens are the increase of free radicals (ROS) in human tissues that gradually causes cardiovascular diseases and cancer by oxidizing large molecules of the body. Considering the importance of maintaining a regenerative balance in cells, they include a network of anti-oxidant defense mechanisms that inhibit the activity of free radicals and prevent them from oxidation, and by deactivating them, immune cells to the damaging effects of these compounds. One of the most important antioxidant mechanisms of the body against the attack of reactive oxygen species is the presence and activity of superoxide dismutase enzyme. This enzyme, in particular, catalyzes the reaction of superoxide anion dismutase to oxygen and hydrogen peroxide. Superoxide dismutase is widely found in plants and animals. The purpose of this research is also to extract and purify the superoxide dismutase enzyme from inexpensive and accessible chicken livers. In general, the removal of dissolved and non-soluble substances from diluted solutions is difficult. For some materials such as proteins and enzymes, this problem becomes more serious due to the sensitivity to changes in operational conditions. Unfortunately, there is no ideal method for the purification of proteins, and usually its purification includes a multi-stage operation that involves losing a lot of enzyme activity. The method of purification with gel chromatography is our proposed methodology in this study, which in addition to minimizing process stages, retains the efficiency of purification and reduces the loss of enzymes activity. According to studies, there is not much information available to purify this enzyme with gel chromatography of chicken livers. The effect of different parameters on the purification of superoxide dismutase enzyme has been investigated by researchers but in this study, pH, chromatography column length, flow rate of transmission solvent, and the concentration of ammonium sulfate salt for deposition of protein solution parameters was considered for two types of G75 and G100 Sephadex gel chromatography as an effective parameter in the amount of purification. Performing high tests always involves spending a lot of time and cost, so that the experiment design was used by Taguchi method. Enzyme activity was measured in different conditions of purification. The values of pH 8, 30 cm length column, flow rate of 60 ml/hr, and 60% w/v of ammonium sulfate salt for the sedimentation of initial extract containing superoxide dismutase enzyme for both types of used Sephadex resulted in the maximum recovery ratio (402.21 recovery ratio for G75 and 605.19 for G100). Electrophoresis was used to evaluate the performance of purification and maintaining enzyme nature. The results of the electrophoresis showed that the enzyme did not lose its activity. Keywords: Purification, Gel chromatography, Superoxide dismutase Enzyme, Taguchi method.