Abstract: Six nutrition compositions of four legumes and six crop straws were assayed. Nutrition value was estimated synthetically by the grading index (GI) from dry matter intake（DMI）and net energy (NE). The results showed that the nutrition value of alfalfa (Medicago sativa), sickle alfalfa (M. falcata) in Longzi and alfalfa (Medicago sativa) in Jiangzi were the highest among the legumes, and the straws of potato (Solanum tuberosum), maize (Zea mays) and oat (Avena sativa) were the higher than other crop straws. Medicago sativa and M. falcata in Longzi in legumes and the three species as above in crop also were the most nutritional species using the method of GI and grey degree analysis method. The result from GI was consistent with that from grey correlation degree.