The article deals with the study of characteristics of epitope-specific humoral immune response to respiratory syncytial viral infection depending on nature of disease and patients' age. The couple serums from 226 children and adults with respiratory syncytial viral infection were analyzed. To detect in enzyme immunoassay the epitope-specific IgG the synthetic peptides were applied imitating the structure of functionally depended epitopes of F-protein of respiratory syncytial virus with amino acid sequences 221-232 (F = SP12), 479-491 (F-SP13) and G-protein with amino acid sequences 152-164 (G-H13), 184-198 (G-T15). The respiratory syncytial viral infection neutralizing antibodies were detected using the microneutralization reaction. The rate of seroconversions of epitope-specific IgG consisted 21-25% in children 3-18 years old under primary respiratory syncytial viral infection and increased up to 42-50% in children 3-18 years old and adults under recurrent episodes of diseases. In these groups, the seroconversions of respiratory syncytial virus neutralizing antibodies were observed in 42%, 65% and 58% of cases correspondingly. Independently of age of patients with diagnosed respiratory syncytial viral infection, the absence of conversions of neutralizing antibodies was statistically significant associated with the absence of response from epitope-specific IgG. The presence among B-cell epitopes of immune dominance of surface glycoproteins of respiratory syncytial virus in patients with recurrent (but not primary) respiratory syncytial viral infection is detected The hierarchy of epitope-specific immune response in case of complicated course of disease (response activity to epitopes: SP12 = G-T15 > G-H13) differed from the case of uncomplicated course of disease.