In order to explore the water regulation mechanism of cotton under salt stress at different growing stages, a potted experiment was conducted to study the shortterm responses of cotton (Jimian 616) growth and water physiological indices to various salinities of irrigation water (NaCl) at different growing stages. The results indicated that when the salinity of irrigation water reached 4 g·L^-1, cotton vegetative growth was restrained; however, the reproductive indices (bud stage and blossoming and bollforming stage) were not affected significantly. The growing process was not affected at the bud stage, delayed at emergence and seedling stages but advanced at blossoming and bollforming stages. In addition, with the increase of irrigation water salinity, stomatal resistance increased at the seedling stage, bud stage, and blossoming and bollforming stage. However, the relative leaf chlorophyll content increased at the seedling stage, first increased and then decreased at the bud stage, decreased at blossoming and bollforming stages, respectively. Salt stress increased the dry weight to fresh weight ratio of all organs except leaves during the whole study period, and the dry weight to fresh weight ratio of leaves basically kept stable. Our results suggest that water in cotton plant could be supplied to leaves preferentially and leaf transpiration was reduced through a water regulation mechanism when cotton was in salt stress.