White spots were observed on the surface of the mantle muscle of European common cuttlefish during freezing storage. To investigate the cause of production of the white spots, several constituents of the spots were analyzed. Octopine, whose content was 42.7%, was proved to be the main component. The total amount of protein and peptide was 25.4%, so they were the secondary major component. Water and ash content were 7.0% and 5.4%, respectively. On the other hand, microscopic studies proved that the white spots were crystaline material like needles.