Climate change and rising temperatures caused water deficits due to lesser and irregular rainfalls, leading to lower production of crops. Morpho-physiological and yield contributing traits of Upland (G. hirsutim L.) cotton varieties grown under optimal water supply (control) and water deficit (experimental) conditions are presented in the article, total chlorophyll, chlorophyll "a", chlorophyll "b", carotenoids, the amounts of proline, malonyldialdehyde, yield per plant, cotton weight per boll, the number of seeds per boll and the number of bolls per plant and the results of their correlation analysis are presented. Under water deficit conditions, there is a strong positive correlation between the carotenoids in plant leaves and the number of bolls per plant, a strong negative correlation between the number of carotenoids and malonyldialdehyde, a strong negative correlation between malonyldialdehyde in plant leaves and the number of bolls per plant, a strong positive correlation between plant productivity and the number of bolls per plant was found to exist. It has been determined that the varieties of Ishonch and Navbahor-2 are more resistant to water deficit than C-6524 and Tashkent-6 in traits of physiological-biochemical and yield attributes.