Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[${alpha}$]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-$17{eta}$ (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P ($10^{-6}-10^{-5}M$) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT ($10^{-9}-10^{-5}M$) the gene expressions of CYP1A and AhR were suppressed at high concentrations ($10^{-6}-10^{-5}M$), while having no effects at low concentrations ($10^{-9}-10^{-7}M$). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-$17{eta}$.