1.The passivating properties of chromate pigments were studied. The irreversible electrode potential of steel in thin layers of aqueous extracts of pigments was displaced by 200–300 mv toward the positive region and became extremely stable with time.2.The potential of steel is greatly dependent on the nature of the pigment. In passivating power the chromate pigments fall into the following series: mixed barium-potassium chromate (technical) ≫ mixed barium-potassium chromate (chemically pure)≫ strontium chromate≫ zinc chromate.3.It was shown that the great differences in the passivating properties of the pigments are due to the differences in the solubility of the passivating parts of the pigments. The CrO3concentration in the extract of a mixed chromate is considerably greater than in extracts of strontium and zinc chromates (10–13 g/ liter instead of 0.5