In this paper, the growth performance and contents of K⁺ and Na⁺ of I. lactea var. chinensis related to salt stress were studied through cultivation on a sand culture experiment. The result showed that the biomass, plant height, dry weigh, carnification, K⁺ content and K⁺/Na⁺ ratios of I. lactea var. chinensis decreased with increasing NaCl stress, while root/shoot ratios and Na⁺ content increased. The water content and carnification degree of roots in all treatments were higher than shoots, which, however, was not significantly related to salt concentration. When the salt concentration was less than 20 g/kg, for I. lactea var. chinensis, the absorption selectivity of K⁺ in roots decreased, but the transportation selectivity to shoots increased. So under NaCl stress, the restrained growth of I. lactea var. chinensis was much related to increased Na⁺ content and decreased K⁺/Na⁺ ratio.