The deistribution of free and conjugated amino acids in the trichloroacetic acid extracts of mature eggs of fish, such as chum salmon, trout, sweet smelt, pond smelt, goldfish, carp, saury, flying fish, puffer, and flathead flounder was examied. The composition of these amino acids fluctuated extensively, but a similarity of amino acid patterns was found among the eggs of fish which are taxonomically close to each other. The eggs spawned in sea water, except for puffer, had higher levels of free amino acids than the others. All eggs contained phosphopeptides, although the yield and amino acid composition of the phosphopeptides varied consierably from species to species; chum salmon and trout were rich in phosphopeptides compared with the other fish eggs. The amino acid pattern of ethanol precipittes obtained from the trichloroacetic acid extracts of many fish eggs resembled that of the phosphopeptides.