Abstract: In order to make full use of the sea cucumber protein resources,sea cucumber guts were used as a raw material,which combined with heat denaturation pretreatment to prepare sea cucumber guts activity polypeptide and explored the effect of heat denaturation pretreatment on the properties of peptides. Using neutral proteases digest the two sea cucumber intestine homogenates(the denatured group with pretreatment at 100℃ for 10 min and non-denatured group),and compared the degree of hydrolysis,soluble protein and trichloroacetic acid(TCA)soluble oligopeptide content,peptide yield,molecular weight distribution,and antioxidant capacity of enzymolysate. And the protein content and reduction capacity of separation were determined. The results showed that,after degeneration,the degree of hydrolysis increased from 23.76% to 37.28%,and the peptide yield increased from 13.97%±1.25% to 25.13%±1.59%. The molecular weight of primary peptide fraction in hydrolysates(denaturated)of sea cucumber guts ranged from 0.5 to 3 kDa which determined by gel filtration chromatography on Superdex Peptide 10/300 GL,accounting for 57.29% of the hydrolysates,and the ABTS⁺ and DPPH free radical scavenging rate up to 0.51 Trolox equi/μL Sample and 90.95%. These results suggested that the sea cucumber guts peptides with low molecular weight,prepared with a combination of denaturing pretreatment and neutrase hydrolysis,would have potential value for exploitation.