Distributions of soil saline ions and vegetation communities were studied in Phragmites communis land.Results indicate that spatial variation of soil saline ions was significant,with variation coefficient of the four types of cations (Na⁺、K⁺、Ca²⁺、Mg²⁺) ranging from 0.60 to 1.22,and of the four types of anion (HCO₃^-、CO₃^2-、Cl^-、SO₄^2-) from 0/35 to 1/41.Among the eight types of ions,Na⁺ was the highest in content among the four cations,and HCO₃^- among the four anions.Comparison between vegetation communities show that Puccinellia tenuiflora + Phragmites communis community was higher than Phragmites communis community in concentrations of the eight ions (p<0.05),and in soil EC,soil pH,plant height,and biomass as well (p<0.01).So with increasing soil electric conductivity and ion concentration,soil alkalinity increases,vegetation growth index decreases,and vegetation community turns from Phragmites communis community to Puccinellia tenuiflora + Phragmites communis community.