In this study,we investigated the organ distribution of ADH activity in three marinefishes,yellowfin porgy(Acanthopagrus latus),grey mullet(Mugil cephalus)and Japanesesea perch(Lateolabrax japonicus).The ADH activities of various organs in the differentspecies displayed a little difference.The liver was the organ that had the highest enzymeactivity in all the fishes.In particular,the liver of M.cephalus showed the highest activity.The kidney and the gill had the lowest ADH activity in all the three fishes.In the muscle,ADH had medium enzyme activity which was about 51-55% of that in the liver.