A method of gel filtration of Sepharose 6B was used; Stokes's radii (a) of some forms of cytoplasmic receptors of estrogens of the uterus, kidneys, and the liver of male and female rats were determined. In the initial cytosol in elution with buffer of low ionic strength estrogenic uterine receptors were presented chiefly by the form with a ∞ 70 Å, and the receptors of the male and female kidneys by the form with a ∞ 30 Å; receptors of the liver of males and females were represented by both forms, in females the content of the form with a ∞ 70 Å somewhat exceeded the content of the form with a ∞ 30 Å. At the same time in the males the form with a ∞ 30 Å prevailed. In elution with a buffer of a high ionic strength the receptors of all the organs under study eluated with a ∞ 20-26 Å. Formation of a form with ∞ 20-26 Å in the case of receptors of the liver of males and the uterus was reversible under the action of a high salt concentration. Receptors of all the organs under study were capable of forming Ca2+ stabilized form with a ∞ 35 Å in elution with a buffer of low ionic power and a ∞ 21-26 Å in elution with a buffer of high ionic strength.