The authors studied distribution of biochemical markers for HP, GC, EsD, AcP genes, polymorphism of GSTT1 (GST-theta 1), GSTM1 (GST-mu 1), locus WNTR of NOS3 gene (alleles A/B) in chronic dust bronchitis patients and in apparently healthy individuals. Genotypes EsD 1-2 and AcP bb individuals were proved to be most prone to the disease. Endogenous resistent factors for chronic dust bronchitis are genotypes GC 1-1, EsD 1-1, AcP bc.