The effect of preparations from embryonic chicken tissue on the dynamic changes in the levels of interleukins: 1β (IL-1 β), 6 (IL-6), 4 (IL-4) and С-reactive protein (CRP) were investigated in vivo, in the blood serum of white female laboratory mice exposed to single total γ-irradiation in a dose of 5 Gy. The experiments found that during the first days after the action of γ-radiation the indices of resistance of the organism undergoe significant destabilizing changes. These changes are manifested by an increase in IL-1β proinflammatory cytokine in response to external influences. However, the rapid decline in its level during the first days after irradiation reflects alterations in its production. The content of the serum IL-4 in all time points was higher than in the intact group. Moreover, the dynamics of its level during the first days after the irradiation was observed. An increased level of CRP was detected 6 hours after the exposure, indicating the dynamic changes of the severity of the inflammatory process. Administration of preparations from embryonic chicken tissue causes a considerable increase in the content of IL-1β and ІL-6 in 3 and 6 hours after the г-irradiation, with stabilization after 12 hours. When using the preparations before an irradiation, a significantly lower level of СRP was detected in comparison to animals that did not get the preparations. When using the embryonic preparations, the stimulation of synthesis of IL-4 was observed, whose level increased in every time of taking blood samples. Possibility for induction of row of cytokines, in particular, IL-1β and IL-6, plays an important role in stimulation of hematopoiesis and provides a basis to consider this substance as an immunomodulator in pathologic immunosuppressive states. The decrease of serum СRP level can indicate the ability to reduce the severity of radiation injury. In the experimental conditions, an embryonic preparation exhibits inertness relative to the healthy organism.