Abstract: Salt characteristics of saline soils in Lingang District, Shanghai were analyzed. Taking experiments of germination and seedling growth of Festuca arundinacea under salt stress under the conditions of phytotron, the effects of supplementary CaCl₂(5, 10, 20, 40, 80 mmol/L) on germination and seedling growth at NaCl concentration(100 mmol/L) stress, specially on the distribution of Na⁺, K⁺, Ca²⁺, Mg²⁺ in roots and shoots, were studied. The results show that proper supplementary CaCl₂(20 mmol/L) can improve seeds germination and seedling growth significantly under 100 mmol/L NaCl, but high level CaCl₂(80 mmol/L) aggravates salt stress. In conclusion, supplementary CaCl₂ with proper concentration added to the solution containing salt significantly improves seeds germination and physiological variables affected by stress(e.g. plant growth and membrane permeability) and also increases K⁺ and Ca²⁺ in plants, but CaCl₂ concentration must low 40 mmol/L, higher level results in adverse effects to the germination and seedling growth, also disturbs the ion homeostasis.