The soluble protein of Leymus chinensis leaf at MD was the greatest, but those at SD, especially very soil drought (VD) significantly were reduced, and the trend of free amino acid (FAA) similar.

• LD处理没有增加天冬酰胺酶(AE)和内肽酶(EP)两种酶的活性，但MD、SD和VD使两种水解酶的活性显著增加，说明轻度土壤干旱对蛋白质和氨基酸的分解作用有稍降低作用，但随着土壤干旱程度的加剧，又极大地促进了这个分解过程。