Objective:In this paper, the inhibition of protein degradation in autolysis of white shrimp (Penaeus vannamei) surimi by extracts from the coelomic fluid of sea cucumber (Stichopus japonicus), a by-product of sea cucumber processing, was studied.Methods:The protein degradation in autolysis of white shrimp was studied by SDS-PAGE assay. Furthermore, the effect of sea cucumber coelomic fluid and its extracts on white shrimp protein degradation was determined by SDS-PAGE and TCA-soluble oligopeptide assay.Results:The optimal conditions of white shrimp autolysis were incubation at pH 3.0, 50 ℃ for 2 h. The bond intensities of myosin heavy chain around (200 kDa) and actin around (44.3 kDa) decreased suggesting the protein degradation of white shrimp. The sea cucumber coelomic fluid showed inhibitory effect on protein degradation in autolysis of white shrimp. When the concentration of coelomic fluid extract of sea cucumber was in the range of 6.25%~25.00%, the protein degradation was significantly inhibited. The release of TCA-soluble oligopeptide was also significantly inhibited by coelomic fluid extract at 12.50%~25.00%.Conclusion:Sea cucumber coelomic fluid extracts possess inhibitory effect on protein degradation of white shrimp, indicating suppression of white shrimp surimi autolysis.