Abstract: Glaucoma caused loss of visual function loss by damaging the optic nerve. Aqueous humor plays an important role in the pathophysiology of the eye. One of the function is to protect eyes from the ultraviolet rays and free radical. Oxidation and free radical and oxygen reactions can effect the activity cell of trabecular meshwork especially endothelial cell. Superoxide dismutases are enzymes involved in the protection against oxidative stress by detoxification of superoxide. The present study was design to determine level activity of SOD in aqueous humor of primary glaucoma patients.