We examined the effect of rhizosphere ventilation and salt stress on the growth of cotton seedings cultivated in nutrient solution. The changes in plant height, root volume, shoot and root biomasses as well as ash content in cotton seedlings were examined to investigate the effect of rhizosphere ventilation on the growth of cotton under salt stress. Salt stress inhibited the growth of cotton and led to decreased plant height, leaf area and dry weight; poor ventilation also decreased plant height, dry weight and mineral element absorption. A further comparison of the effect of rhizosphere ventilation and the combined effect of rhizosphere ventilation with salt stress showed a prominent effect of salt stress on plant height and total biomass, with a striking effect of rhizosphere ventilation on root volume, root biomass, root-to-shoot ratio and mineral element absorption (i.e., the adverse effect of salt stress was mainly exhibited on stems and leaves, and that of rhizosphere ventilation on root growth). In addition, the variation in cotton seedlings in terms of plant height, root volume, leaf area, root biomass and total biomass in the rhizosphere ventilation conditions was smaller than those in seedlings without ventilation. Rhizosphere ventilation could increase plantlet height, leaf area, dry weight, thereby alleviating the adverse effect of salt stresses.