Abstract: Industrial cultivated Pleurotus eryngii by-products were analyzed in contents of major nutrients, and estimated particularly in its protein value with non-biological evaluations.The results showed that, compared with commodity P.Eryngii mushrooms, the cultivated P.eryngii by-products contained similar nutrients in amount of ash, crude fat, crude polysaccharide, Ca, Fe, Zn and Se but higher in its crude protein than in the commodity mushrooms for 20.69%.The P.eryngii by-product contained 17 amino acids in total amino acids and total essential amino acids for 16.38g·hg-1 and 6.16g·hg-1, respectively.By indices of chemical score (CS) , amino acid score (AAS) and ratio coefficient of amino acid (RCAA) , the first limiting amino acid of P.eryngii by-product was determined in sulfur amino acids (methionine and cystine) , and higher in lysine and threonine than in other amino acids.The results suggested the optimal application in use of the by-products as the complementary of grains food.Comparatively, the indices of essential amino acid index (EAAI) , biological value (BV) and score of ratio coefficient of amino acid (SRCAA) were slightly lower in P.eryngii by-product than in commodity mushrooms, while nutritional index (NI) was slightly higher in P.Eryngii by-product than in commodity mushrooms but was similar with it of shiitake mushroom.The nutritional information indicated that Pleurotus eryngii by-product had great potential for further development in use.