Abstract: Objective To explore molecular chracteristics and distribution of Mycobacterium tuberculosis(M.tuberculosis) in Lanzhou area,Gansu province with traditional 43-space spoligotyping.Methods Totally 215 M.tuberculosis strains were ioslated from confirmed patients in Lanzhou Pulmonary Disease Hospital and were genotyped by traditional 43space spoligotyping.The characteristics of DNA fingerprinting of the strains was analyzed with BioNumerics 4.5 softw are.The results were compaed with International Spoligotyping Datebase (SpolDB4).Results Of all the strains,86.98% (204/215) were grouped into 11 clusters(spoligotypes) with other 11 unique strains.Among 22 spoligotypes(STs),12 spoligotypes were cluster strains,while 10 spoligotypes(14 strains) were new and unique(orphan).Beijing family genotype was the most common genotype family(86.51%),follow ed by T family(4.19%),H family(1.86%),and MANU family (1.40%).Multivariate logistic regression analyses showed no statistically significant association between the Beijing family genotype strains and resistance to all of four drugs(rifampicin,isonizid,ethambutol,and streptomycin),patient's gender,age,job,residence of the patients,antituberculosis therapy history,regular or irregular therapy,and new cases or relapse cases.Conclusion The strains of M.tuberculosis isolated in Gansu province present definite gene diversity.Beijing family genotype is the most epidemic genotype in the region and other genotypes of M.tuberculosis should be emphasized to prevent and control the spread of other spoligotypes strains.