In order to select suitable salt-tolerant plants for the improvement of coastal saline soil, the characters for ions absorption and accumulation in four typical salt-tolerant plants (Suaeda salsa, Sesbania, Kenaf and Sudangrass) was explored by field experiment. The results showed that in seeding stage and maturation period, the aboveground biomass of each plant accounted 80% more of the total dry matter, in an order of Sesbania > kenaf > Suaeda salsa > Sudangrass. Sudangrass and Kenaf had higher capacity of absorption and transportation of K⁺ and Ca²⁺ while Sesbania and Suaeda salsa had higher capacity of Na⁺. The accumulation of K⁺ was higher than other ions in Sudangrass. K⁺ was the main ion accumulated in seeding stage of Sesbania, Na⁺ and Cl^- were the main ions accumulated in maturation period. Cl^- and K⁺ were the main ions accumulated in Kenaf. Na⁺ and Cl^- were the two main ions accumulated in Suaeda salsa, and the ratios of these two ions to the total accumulated salt amount were highest among these four plants. From seeding stage to maturation period, ratio of Na⁺ decreased while ratio of Cl^- increased in Suaeda salsa, the ratios of Na⁺ and Cl^- increased in Sesbania and Sudangrass but decreased in Kenaf. In general, Suaeda salsa, Sesbania and Kenaf are the sound plants for the improvement of coastal saline soil.