The nutritional and functional properties, molecular weight distribution of protein hydrolysate from Tra fish by-products were studied. The protein hydrolysate was produced by enzymatic hydrolysis of Tra fish by-products with Protamex 0,5% at the temperature of 50 oC in 6 h. The study results showed that the Tra fish by-products protein hydrolysate had a moisture content of 6,7%, protein content of 65.8%, lipid content of 1,6% and ash content of 9,5 %. The protein hydrolysate had a total amino acid content of 52,81 g/100g of protein and essential amino acid content of 16,25 g/100g of protein. The ratio of essential amino acids to total amino acids was 30,76%. The protein hydrolysate was rich in glycine, glutamic, proline, alanine, aspartic and leucine. The most of peptides (68,25%) in Tra fish by-products protein hydrolysate had a molecular weight between 360 Da and 2.500 Da. The protein hydrolysate had solubility in the range of 90,3% - 98,2%. The solubility of protein hydrolysate was the lowest value at pH 4 and the highest value at pH 10. The foaming capacity of protein hydrolysate ranged from 19,5% to 27,8%. The emulsifying capacity of protein hydrolysate was 12,8 – 17,3 mL/g. The protein hydrolysate of Tra fish by-products possesses high nutritional value and good functional properties. The study results suggested that the protein hydrolysate from Tra fish by-products could be used as a promising food ingredient and protein source in food systems.