Abstract: The standard 12-locus mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR) was performed on 184 M. tuberculosis clinic isolates that were randomly selected from the collection during 2009-2013 in Sichuan to evaluate the stability of the set of the first-line typing loci used in this region and detect the set of conservative loci and the predominant MIT. The study showed that 184 isolates were divided into 51 genotypes and 12 clusters, and confirmed that the 7 MIRU loci that were included in the adjusted scheme of the 12 highly discriminatory VNTR loci were effective (h > 0.55) and the 4 poorest discriminative loci were MIRU02, MIRU20, MIRU23, and MIRU24 (0 ≤ h