To evaluate nutritional value of Monochamus alternatus in different developmental stages, the contents of water, crude protein, crude fat, carbohydrate, fatty acid, amino acid and inorganic element of Monochamus alternatus were determined. The results showed that Monochamus alternatus larva, pupa, female adult and male adult respectively contained 69.69%, 61.26%, 55.10% and 51.76% water; respectively contained 37.81%, 46.36%, 67.82% and 69.85% crude protein; respectively contained 33.96%, 27.73%, 11.94% and 9.83% crude fat; respectively contained 62.483%, 61.988%, 43.977% and 44.049% oleic acid，including 8.156%, 6.356%, 13.138% and 13.103% essential fatty acid respectively. The total amino acid contents were 346.70, 414.94, 625.93 and 650.21 mg/g, respectively in larva, pupa, female adult and male adult Monochamus alternates, in which the total essential amino acid contents accounted for 35.99%, 36.40%, 31.56% and 32.00% of the total amino acids, respectively, while the delicious amino acids accounted for 12.13%, 15.48%, 22.26% and 23.33% of the total amino acids, respectively. The ratio of essential to nonessential amino acids was 0.562, 0.572, 0.461 and 0.471 for larva, pupa, female adult and male adult Monochamus alternates respectively and the essential amino acid index was 100.11, 87.49, 84.40 and 85.12, respectively. Monochamus alternatus had rich trace elements. The larva had the highest Ca and Mg concentration which was 894.62 and 2994.52 mg/kg, respectively. The female adult had the highest Zn and Fe concentration which was 116.54 and 265.20 mg/kg, respectively. The male adult had the highest Cu, Mn and Se concentration which was 91.76, 37.90 and 128.00 mg/kg, respectively. In conclusion, Monochamus alternatus had high nutritional value.