Abstract: The plant growth reduced in salinity by inhibition in nitrogen, phosphate, potassium up take, but little study of supplemental nitrogen effects with plant was available. Plant growth and the contents of several nutrient ingredients which included nitrogen, phosphorus, potassium, free amino acids, soluble sugar,soluble protein and total anthraquinone in leaves of Aloe vera seedlings by 200 mmol·L ^-1 NaCl stresswith different concentrations of NH₄NO₃ were studied. The results showed that the plant dry mass was increased with the application of NH₄NO₃ (3.75 - 18.75 mmol·L ^{- 1} ) under salt stress, i. e. supplemented nitrogen promoted salt tolerace of Aloe vera seedlings. Increased with nitrogen level, content of nitrogen, phosphorus, potassium, free amino acids, soluble sugar, soluble p rotein and total anthraquinone in leaves were increased obviously and reached the maximum value at 11.25 - 15 mmol·L ^{- 1} NH₄ NO₃ level while the excessive NH₄NO₃ application ( 18.75 mmol·L^-1 ) led to the negative effect. It appeared distinct difference among different-site leaves for the content of nutritional ingredients. Content of total P, thraquinone and soluble protein in the upper leaveswere higher and the same with soluble sugar in mid leaves, total N in down leaves. Nitrogen, phosphate, potassium increase in Aloe vera leaves with supplemental NH₄NO₃ in salinity played an important role in maintaining ion homeostasis, nutrient content and cell potential, while free amino acids, soluble sugar and soluble protein was significant organ osmoticas in plant responsing to salt stress. In some extent, high salt tolerance of Aloe vera was improved by supp lemental N was main caused by the enhancement of N, P, K, free amino acids, soluble sugar and soluble protein content in leaves.

Key words: Aloe vera, Salt stress, Salt tolerance, NH₄NO₃, Growth, Nutrient, Quality