Abstract: Objective To investigate regulative effects of sea cucumber powder on immune function in normal mice.Methods Totally 200 male specific pathogen free Kunming mice were divided randomly into four groups:a control group and high,moderate,and low treatment groups with 0.33,0.67,and 1.00 g/kg sea cucumber powder administered by oral gavage for 30 days.The splenic lymphocyte tranformation efficiency and activity of natural killer(NK)cells were determined with methylthiazolyldiphenyl-tetrazolium bromide(MTT)method.The delayed type hypersensitivity (DTH)and the impacts of T cell subgroups were induced with dinitrofluorobenzene(DNFB)method.The humoral immunity function was determined with serum antihemolysin and antibody-forming cell assay.Non-specific immune function was detected with monocaryon-macrophage cell and reticuloendothelial system phagocytosis.Results Compared with the control group,there were no significant changes in body weight in the mice of the three groups with sea cucumber powder treatment.There were no significant changes in thymus gland index,spleen index,and ear-swelling test.Compared with the control group,the splenic lymphocyte tranformation efficiency and NK cell activity were 0.378±0.125,0.370±0.096 and 57.24±7.31,57.54±7.29 for moderate and low dose treatment groups,and all were higher than those of the control group(P<0.05); the carbon clearance index of the mice in low and high dose treatment groups were 6.18±0.86 and 6.25±1.21,with significantl improvement(P<0.05).Conclusion Sea cucumber powder has some regulative effect on immune function and can enhance cellular immunity function in mice.