A by-product is a secondary or incidental product deriving from a seafood manufacturing process, due to the by-product has low value, low yield and high price for recovery these difficult problems, therefore most of the by-product is regard as waste. In order to give the by-product of sea cucumber efficient application and raise the additional value of it, so in this research we estimated the efficacy of the internal organs and body wall of Holothuria atra. Crude protein was the major portion of the body wall, and the ash as follow. The acid-insoluble substance of internal organs was 0.14%, and none detected in body wall. The internal organs of H. atra were hydrolyzed with A and B enzyme groups, while the hydrolyte of B enzyme group had no bitter flavor, so we suggested that it agreed with applying for health food. The hydrolyte of B enzyme group had good antioxidative abilities, and it also could activate the proliferation and IgM antibody secretion of HB4C5 cell, activated the proliferation of J774.1 cell to 160% and induced the NO secretion of BAEC cell. In animal test, the hydrolyte of B enzyme group can elongate the swimming time of mice, and the concentration of creatitine, urinary urea nitrogen and lactate in serum was no effect, and there was also no effect on immunomodulatory. The glycosaminoglycan in body wall was 4.2% (dry base), and it was composed of 73% soluble protein, 1% hexuronic acid, 10% fucose and 16% hexosamine.