Starch gel electrophoresis of hemoglobins of many kinds of fishes and whales was carried out using the sample solution of cyanmethemoglobin. As to the hemoglobins of fishes, for example, chum salmon and eel, that had been thought to be composed of two components by analysis of TISELIUS electrophoresis, they were clarified to have two groups, one group moving to anode and the other group to cathode, each of which separated into more than two components by starch gel electrophoresis. Remarkable differences were also observed among three species of tuna which are classified in one genus, Thunnus. As far as studied here, there was no fish whose hemoglobin consists of a single component. It might be said that fish has more hemoglobin components, compared with higher vertebrata.