Abstract: Objective To study the relationship between genotype and drug resistance of M. tuberculosis representative strains in Ningxia, and to investigate their molecular epidemiological characteristics. Methods One hundred and fifteen M. tuberculosis clinical isolates were collected in Ningxia, and analyzed their genotypes by spoligotyping and drug susceptibility by the proportional method. The chi-square test was used to compare the differences among the results of different groups. Results Of 115 M. tuberculosis isolates, 90 (78.3％) isolates belonged to Beijing genotype, 25 (21.7%) isolates belonged to non-Beijing genotype. Of 90 Beijing genotype isolates, 41(45.6%) isolates belonged to the ancient genotype, in which drug-resistant rate was 17.8% (16/90); 49 (54.4%) isolates belonged to the modern genotype, in which drug-resistant rate was 36.7% (33/90). There were no significant difference of drug resistances between different genotypes（χ²=1.27，P>0.05). Conclusion M. tuberculosis Beijing genotype was the predominant in Ningxia. There was no significant relationship between Beijing genotype and drug resistance.

Key words: Mycobacterium tuberculosis, Genotype, Drug resistance, bacterial, Genotyping techniques, Ningxia