The purpose of this study was to investigate the effects of temperature reduction on immune enzymes, soluble sugars and soluble proteins in sea cucumber (Apostichopus japonicus) preliminarily. Two temperature reduction modes were adopted. Sea cucumbers were designed to do cooling program including mild temperature and acute temperature inside. The result showed: (1) There was significant effect of two temperature reduction modes on the content of soluble proteins in the body wall of sea cucumbers (P<0.05). In the process of acute temperature reduction, the different magnitudes of temperature reduction (9.5℃, 5.5℃, 3.5℃) were significantly affected the soluble sugars and soluble proteins (P<0.05). In the process of mild temperature reduction, soluble sugars and soluble proteins varied obviously at 2℃. (2) There was a significant effect of two temperature reduction modes on the activities of CAT and SOD in the coelom fluid of sea cucumbers; The different magnitudes of temperature reduction significantly affected the activities of CAT, SOD and AKP in the coelom fluid of sea cucumbers (P<0.05) at the process of acute temperature reduction. The activities of several immune enzymes changed gradually with the decrease of acclimation temperature at the process of mild temperature reduction. Temperature below 2℃-4℃ and the temperature reduction with 9.5℃ had a significant effect on the immune and physiological indexes of the sea cucumber. Mild temperature reduction had smaller influence on the immune indexes of sea cucumber than acute temperature reduction does.