The mol. wt. of high density lipo-protein of hen, trout and cuttlefish eggs were determined as 330,000,360,000 and 2,500,000 respectively. The lipid moiety of the lipoproteins were rich in phospholipids (58-65%, but poor in cholesterol (0-4%). The nonlipid moiety of hen, trout and cuttle-fish lipoproteins was analyzed: P, 0.69, 0.42, and 0.73; N,16.1, 14.5, and 12.9; carbo-hydrate, 0.75, 0.25, and 12.6%, resp. The cuttlefish lipoprotein was characterized by higher content of carbohydrate.