The effect of continuous single and combined influence of exogenous stress factors (ethanol and low intensity gamma-radiation) on cytochrome P450 2E1 (1.14.14.1) expression in mice liver was studied. The chronic ethanol intake induced Cyp2E1 protein expression but not increased Cyp2e1 mRNA level. The first week of continuous combined influence of ethanol and gamma-irradiation was characterized by the increase of Cyp2E1 protein level, that was back to normal on second week. A small decrease of this index was observed at the end of the fifth week. The changes of Cyp2E1 protein amount accompanied the decrease of Cyp2e1 mRNA level.