The article concerns studies on suppression of immune response to a certain antigen with application of auto- logic anti-idiotypic antibodies. The experiments were carried out on the male rabbits of "Shinshilla" species. The animals were immunized with bovine serum albumin (BSA), immunoglobulins were precipitated from the blood, anti-BSA polyclonal antibodies were purified using the technique of immune affinity chromatog- raphy, they were digested with the enzyme (pepsin) and F(ab)2-fragments of the anti-BSA antibodies were purified using the technique of gel-chromatography. Immunization of the rabbits with F(ab),-fragments of the anti-BSA autologic antibodies led to significant downregulation of the earlier induced immune response to BSA.