The results of the study of the main regulatory cytokines levels in patients with chronic forms of EBV-infection (CEBV) are presented the work.Aim of research. To establish the types of immune reaction for prognostication of the clinical course of disease in patients with chronic forms of EBV-infection on the base of the analysis of multidirectional synthesis dynamics of anti-inflammatory cytokines (IL-1β, TNF-α, IL-6), regulatory IL-2 and anti-inflammatory cytokines (IL-4 and IL-10).Methods. The research oт the study of the main cytokines levels by IEA method in the disease dynamics included patients with EBV-infection (n=80). The serum concentrations of studied cytokines: IL-lβ, TNF-α, IL-6, IL-2, IL-4, IL-10 were determined using test-systems by LTD “Protein outline” (Saint Petersburg, Russia), using the producer's instruction, by sIEA.Statistical analysis of the results of research was carried out using the program Statistika 6.0 for Windows (Stat Soft Inc, USA).Results. The analysis of cytokine profile dynamics in patients with EBV-infection allowed reveal the multidirectional changes of synthesis of studied anti-inflammatory and proinflammatory cytokines that became a base for establishing of two types of immune reaction: dissociative and hyporeactive. Dissociative type was characterized with the low parameters of anti-inflammatory cytokines and regulatory IL-2 on the background of moderately increased values of anti-inflammatory cytokines, whereas the hyporeactive type was characterized with the low concentrations of all studied parameters. Conclusions. The received results of researches prove the existence of cytokine imbalance at EBV-infection. The established types of immune reaction testify to the inadequate cellular-humoral reactivity of organism under conditions of EBV prolonged persistency that is manifested by inclination to suppression of cellular-mediated and intensification of humoral mechanisms of immune response and is reflected in clinical-biochemical manifestations of disease that results in prolonged wavy course.Just the functional imbalance of immunity links to the priority of Тх2 type, which biological effects are directed on the limitation of intensity and prevalence of inflammatory process in different organs, favors the prolongation of viral persistency.