Abstract: The nutritional evaluation of blood-cell protein from Tachypleus tridentatus(TTBCP)was carried out,and its antioxidant activities,the inhibitory activities on α-glucosidase and acetylcholinesterase were measured in vitro. The results showed that the essential amino acids in TTBCP were superior to the adult's FAO/WHO-recommending model,basically conforming to the child's FAO/WHO-recommendating model. The ratio of essential amino acids to total amino acids(E/T)was 31.2%,the amino acid score(AAS)was 68.1,the protein efficiency ratio(PER)was less than 2.0. The half inhibitory concentration(IC₅₀)of TTBCP on α-glucosidase was 0.199 mg/mL with the highest inhibition rate of 83.8 mg/mL. TTBCP also had inhibitory effect on cholinesterase. The hydrolysate peptide of TTBCP could scavenge the superoxide anion radicals,DPPH radicals and hydroxyl radicals,its reduction ability was greater than vitamin C when the concentration was less than 0.75 mg/mL. So,TTBCP could be developed into a health food and medicine for diabetes mellitus owing to its comprehensive efficacy.