Abstract: Salinity is a big threat to world agriculture. It imposes a major setback in increasing the yield of cotton. This crop is very sensitive to salinity at germination and seedling stage. Salt stress adversely affects the biomass production, i.e., decrease in leaf area, stem thickness, shoot and root weight and ultimately brings about decrease in seed cotton yield. A threshold salinity level at which initial yield of cotton declines is 7.7 dS m-1 with a 50% reduction in yield at 17.0 dS m-1. Reduction in fibre length, fibre strength and micronaire values, whereas an increase in ginning out-turn have been reported under saline conditions in both Gossypium hirsutum and Gossypium barbadense. High salinity level adverse affects photosynthesis. Research studies indicate decrease in nitrogen of leaf cotton with increasing salinity levels. Salinity increases Na+ and Cl¯ and decreases K+, Ca2+ and Mg2+ in leaves of cotton. Slight increase in K+ and modest accumulation of Na+ with increase in salinity have also been found in literature. K+/Na+ ratio has been used as a successful selection criterion for salt tolerance in some crops. Generally salt tolerance in cotton has been associated with Na+ exclusion. High salinity reduces N and P uptake in cotton, whereas low salinity does not have a significant effect on the absorption of either of the ions.