Adaptation of plants to the action of gamma-irradiation and cadmium chloride has been studied in the experiments on water culture of maize plants. A new method of registration of the biological object state at the conditions of the stress-factor action - "the method of radiocapacity factor" based on the measurement of the culture medium radio-activity during the incubation process of vegetative objects has been developed. The method offered has allowed us to estimate in dynamics an integrated condition of the root system exposed to stimulating and inhibiting doses of acute gamma-irradiation. Application of the pattern of radio-adaptive response has allowed us to reveal it using both a conventional technique - by registering the values of growing parameters, and the radiocapacity factor method.