Immunological parameters of laboratory mice in health and under different pathological statuses were investigated. The comparative analysis of immunological parameters of nonpregnant and pregnant mice showed, that statistical decreasing of leucocytes and lymphocytes amount was fixed under physiological pregnancy. The investigation of immunity parameters under pathological statuses (exogenous microbial load, extragenital pathology and antibiotic load) showed mostly the changing of next parameters: full amount of leucocytes, the amount of circulating immune complexes and data of NST-test. The comparative analysis of data received under pathological statuses showed that the most efficient depression caused by extragenital pathology.