The materials carcinogenic agent, nitrosoamine, is distributed in food circumstances, and is formed when both nitrite and secondary amine are present. Nitrites are added to fishes as a color fixative or preservative and secondary amines exist in fishes. In order to find the distribution and contents of secondary amines, analysis of 19 kinds of fish was conducted. The results showed that, significant differences were not observed in the quantity of secondary amines in 19 kinds of fish by district. The highest value was 20.29 ppm in Theragra chalocogramma and the lowest was 0.022 ppm in Ostrea denselamellosa. Six fishes below 1 ppm were Nibea imbricata, Misgurnus mizolepis, Astroconger myriaster, Evynnis Japonica, Ostrea denselamellosa and Solen gouldi. Dimethyl amine only was identified and diethylamine or diphenylamine was not detected in all kinds of 19 fishes.