Abstract: To study the nutrient composition of leaves from five kinds of forage grasses, evaluate the nutrition value of amino acid, and provide a scientific basis for the development and utilization of forage grasses fodder, crude protein, amino acid, crude fat, Ca and P were measured by conventional method, neutral detergent fiber and acid detergent fiber were measured by filter-bag method, the nutrition value of amino acid was evaluated by essential amino-acid scoring and chemistry scoring. The results indicated that: (1) the contents of CP, Ca, NDF and ADF were significantly different, the content of CP of water hyacinth was the highest, and CP contents in two kinds of leguminous forages grasses were significantly higher than that in gramineous forage grasses, while ADF contents in leguminous forages grasses were significantly lower than that in gramineous forage grasses; (2) there were amino acids of full range in the forages grasses, the contents of total amino acids and essential amino- acids were rich, methionine was the limiting amino acid in forages grasses. The conclusion showed that (1) CP content in water hyacinth, alfalfa and kudzu were higher, which could be used as feedstuff; (2) Italian rye and hybrid wolftail could be developed as coarse fodder; (3) methionine or methioninerich raw material should be added when producing complete formula feed for animals with the five kinds of forage grasses.