By Chromatographic separation of cytosol fraction of homogenates from gonads of females and males of green sea urchinStrongylocentrotus droebachiensis using an AcA-34 ultragel, protein fractions with mol. mass of 123 and 81 kDa are revealed, which have activity of calciumactivated proteinases. Dynamics of activity of the calcium-activated proteinases is studied during annual sexual cycles of the sea urchin. It is shown that the maximal activity of the studied enzyme in females and males of the sea urchin is present at the IV stage of gonad maturation, at the period of their trophic growth which is characterized by formation of stores of nutritient substances necessary for the subsequent development of embryos.