Two new sulfated saponins designated as certonardosides P$_{2}$ and I$_{3}$ (1 and 2) were isolated from the brine shrimp active fraction of the MeOH extract of the starfish Certonardoa semiregularis. The structures were determined on the basis of spectral analysis. Compounds 1 and 2 were tested for cytotoxicity against five human tumor cell lines (A549, SK-OV-3, SK-MEL-2, XF498, and HCT15), and compound 1 displayed significant cytotoxicity against the SK-MEL-2 skin cancer cell.