The current study measured the contents of main nutrient components in the skin of O. keta by focusing on proteins, common amino acids, hydroxyproline, fat, vitamins, and mineral ions. The results showed that the contents were composed of 31.10% crude protein, 7.40% crude fat, 1.20% ash, 0.23% of total carbohydrate, and various delicious amino acids. There was 682.1 mg/g total amino acids in dry sample having the highest Gly content (185.0 mg/g), followed by Glu (75.8 mg/g) and then hyp (19.3 mg/g). The ratio of EAA/TAA is 22.4% and the ratio of DAA/TAA is 53.7%. The skin has rich collagen content of 214.2 mg/g based on wet weight, accounting for 68.9% of the crude protein. The content of UFA was 10.8%, and the results also indicated that the skin of O. keta was also rich in vitamin B3 (75 mg/kg) and mineral ions such as Ca, Na, Fe, Zn, etc. In summary, the skin of O. keta has high nutritional value, which is a good source for extracting collagen that is widely used in medical, food and chemical industry.