Level of circulating immunological complexes and their immunoglobulin content have been determined in 36 asthmatic patients, including 15 patients with atopic asthma and 21 patients with infectious asthma. A technique of staphylococcal protein A binding has shown, that the level of the circulating immunological complexes is increased in patients with infectious bronchial asthma. An amount of IgE in these complexes has been increased in both atopic and infectious bronchial asthma. However, a level of IgE-containing immunological complexes has been higher in the atopic asthma, then that in infectious form of the disease. An increased IgA content in the immunological complexes has been noted in the infectious asthma.