Goal : to study prevalence and specific regional features of genetic structure and drug resistance of M. tuberculosis of Haarlem family, circulating on the territory of Saratov Region. Materials and methods . Genotyping of 152 clinical isolates from sputum of active mostly new pulmonary tuberculosis patients was performed using hybridization on the biological mircochip with reagents of Spoligo-Biochip (OOO BIOCHIP-IMB, Moscow). Results . It was found out that among genetically heterogeneous strains of M. tuberculosis circulating on the territory of Saratov Region, mycobacteria of Haarlem family were registered in 23.7% of cases, i.e. practically in each fourth patient. Mycobacteria belonging to this genotype were characterized by genetically diverse structure of strains, which could be the evidence of their circulation on this territory for a continuous period of time. Mycobacteria of Haarlem family prevailed in the patients with destruction of lung tissue and positive results of sputum tests (86.1%), and multiple drug resistance was especially high in these mycobacteria (25%), which was typical of Saratov Region since according to data of other studies mycobacteria of Haarlem family were of low virulence and more associated with drug susceptible forms of tuberculosis.