To investigate the relationship between matrix metalloproteinase (MMPs) and autolysis of sea cucumber Stichopus japonicus, the dermis homogenate was incubated at $25^{circ}C$ to induce autolysis. EDTA $Na_2$ and 1,10-phenanthroline were used to verify the effect of MMPs on autolysis, which was measured by soluble protein and protein pattern. Soluble protein level increased during a 6-h autolysis process. SDS-PAGE demonstrated obvious protein degradation with the concomitant occurrence of degradation products. The above two indicators could be inhibited significantly by EDTA $Na_2$ and 1,10-phenanthroline, indicating that MMPs might play a significant role in autolysis of sea cucumber.