In this article, we studied the responsiveness of the antioxidant system of the biotechnological cotton variety to salt stress. We compared the reaction of two salt-resistant cotton varieties to elevated concentrations of sodium chloride (NaCl) and sodium sulfate (Na2SO4). To obtain more complete information about the resistance of the biotechnological variety to salt stress, we analyzed the activity of certain enzymes in the antioxidant system as well as the level of malondialdehyde (MDA). Plants respond to salt stress through the highly regulated protective enzymes such as MDA and superoxide dismutase (SOD), which enhance their ability to neutralize reactive oxygen species (ROS). Such abiotic stressors disrupt the ionic and osmotic balance of the cells. In this study, the activity of the antioxidant system of cotton (MDA and SOD) was determined in the leaves of seedlings grown in the laboratory under saline conditions. The stress resistance of plants and the accumulation of antioxidant enzymes in cotton have been thoroughly investigated in various experiments. The plant material used in this study was the Porloq-4 cotton variety, developed through individual selection of lines obtained by crossing the RNAi Coker-312 line with the commercial Namangan-77 variety. The object of this study was the modified Porloq-4 cotton genotype, while the parental Coker-312 genotype served as the control. Findings indicate that Porloq-4 and Coker-312 cotton varieties respond differently to stress induced by NaCl and Na2SO4 and their combination, with Porloq-4 exhibited a more active and responsive antioxidant enzyme system.