The present invention relates to the field of pharmaceutical technology, in particular to an anti-tumor compound of triterpenoid saponins (the molecular formula is C₆₀H₉₆O₂₈) which is separated from the gray sea cucumbers and is named as griseaside A, a chemical structure is as the right, the chemical structure and a spatial configuration of the compound are determined by a plurality of modern spectral analyses, particularly by a plurality of advanced two-dimension nuclear magnetic resonance spectroscopy comprehensive analyses. The in vitro anti-tumor tests show that the compound has significant inhibiting effect for four tumor cell strains of A-549 human gastric carcinoma cells, HL-60 human acute promyelocytic leukemia, Molt-4 human T lymphocyte leukemia cells and BEL-7402 human hepatoma cells, etc. The present invention can provide a lead compound for the development of new anti-tumor drugs and has important value for the development and utilization of marine medical resources.