<正> Cold-adapted protease MCP-01 is susceptible to autolysis at temperate temperature, which resulted in a lot of difficulties for its purification, preservation and research on its structure and function. Therefore, it is necessary to find approaches to prevent its autolysis. In this article, trehalose was selected to study the prevention effect on the autolysis of cold-adapted protease MCP-01, which was monitored by capillary electrophoresis. Protease MCP-01 autolyzed rapidly at 35℃. After incubated at 35℃for 20 min, 75.7% of protease MCP-01 autolyzed into peptide pieces. However, when trehalose was added, the autolysis of MCP-01 was remarkably prevented. Among three trehalose concentrations--0.25, 0.5 and 0.75 M, 0.5 M trehalose had the best effect. 80.9% of protease MCP-01 still remained after MCP-01 was incubated at 35℃for 2 h in the presence of 0.5 mol/L trehalose. Trehalose has good potential in the research and application of cold-adapted protease MCP-01.