The aim of this work was the determination of the state of local immunity in periodontal complex in patients with chronic generalized periodontitis (CGP). 96 individuals were examined (mean age 43.6+/-1.2 years). All the patients were divided into 2 groups: basic group with CGP patients (76 persons) and comparative group - individuals with intact periodontium (20 persons). To evaluate local immunity in dentogingival fluids the determination of concentrations of IgG, IgM, and IgA immunoglobulins has been used, as well as TNF-alpha, IL-1, IL-6, IL-8, INF-gamma, IL-1ra, IL-10, and IL-4 cytokines, and also factors controlling the state of bone tissue, namely, osteoprotegerine (OPG), and RANK-ligand. In gingival fluid of CGP patients the increase in both pro-, and anti-inflammatory mediators with indication to Th2-deviation (decrease of INF-gamma level and elevation of IL-4 level) was observed. CGP patients exhibited in their periodontal complex marked increase of IgG, IgM, and IgA concentrations that apparently evidenced to the consequence of local polyclonal activation of B-lymphocytes. Gingival fluid of CGP patients showed the elevation of RANKL, TNF-alpha, and IL-1 levels, and the decrease in OPG concentration that could be the reason for osteoclast activation and subsequent destruction of bone tissue. In case of CGP in the zone of periodontium developed <<atypical>> inflammation that is characterized by elevated level of IL-8 and predominance of neutrophil number over the quantity of other types of leukocytes.