The stress tolerability and characteristics of Leymus chinensis seedling were studied with a simulating ecological method.For causing ecological condition of saline-alkali stress,the seedlings of Leymus chinensis were irrigated respectively with the Knop culture solutions con- taining various amounts of Na_2Co_3 at the stages of one-leaf,two-leaf,three-leaf and four leaf in successive order.Then the strains of the seedlings suffering from saline-alkali stress were observed,determined and analysed physiologi...