Four triterpene glycosides from sea cucumbers belonging to the genus Cucumaria, okhotoside A(1)-1 (1), cucumarioside A(0)-1 (2), frondoside A (3) and cucumarioside A(2)-2 (4) inhibit the activity of nonspecific esterase of mouse spleen lymphocytes. The dependence of the inhibitory activity of the glycosides on their structure is similar to that for hemolytic activity. The absence of inhibitory activity for the preparation Cumaside, which is a complex of cucumarioside A(2)-2 and related compounds with cholesterol, shows a cholesterol-dependent character of the inhibitory action of the glycosides. The effective inhibitory concentrations of frondoside A and cucumarioside A(2)-2 are significantly higher than the immunomodulatory doses of these glycosides.