The article studies the effect of 17, beta-estradiol on the binding of cytosol estradiol-receptor complex with chromatin isolated from the liver of female albino rats (sham-operated, ovariectomized and treated after the ovariectomy with 20 micron hormone/100 g body weight for 11 days) and sexually mature male albino rats. Higher binding of the complex is found for the female animals compared with the males. Parallel experiments are made to study the incorporation of 3H-thymidine and 14C-glycine in vivo, in acid-soluble and acid-insoluble liver fractions of female rats, respectively, which is used as a basis for assessing the rate of DNA and protein synthesis. Ovariectomy induces considerable reduction of the binding of the estradiol-receptor complex with chromatin, as well as of the DNA and protein synthesis. Hormonal treatment of the ovariectomized rats is followed by substantial increase in the parameters investigated above the level measured in intact animals. The observed effects of the hormone on the liver correspond to the accepted view concerning the action of steroid sex hormones on their target organs.