An estuarine food chain of threetrophic levels–algae (Platymonas sp.), rotifers (Brachionus plicatilis) and mysids (Neomysis awatschensis Brandt) was setup in laboratory in order to investigate contributionsof water and food to the accumulation of butyltins inupper trophic organisms, as well as to evaluate thelikelihood of biomagnification of butyltins throughthe aquatic food chain. Kinetics of bioaccumulationand depuration of butyltins through the food chainwere studied. Bioconcentration factors of butyltins inthe three organisms were high (103–104).Butyltin burdens in the upper trophic organisms atsteady-state of bioaccumulation by the ingestion oftainted food exceeded those observed by exposure towater only. For total butyltins, food chain transfernumber was 1.44 for algae to rotifers and 0.59 forrotifers to mysids, respectively. Biomagnification wasnot confirmed. It is concluded that whether or notbiomagnification occurs depends not only on theproperty of compounds but also on the organisms involved.