Abstract: Objective To explore the relationship betweenisoniazid(INH)resistance and Ka Gt gene mutation in Mycobacterium tube rculosis.Methods To tally 238 sputum samples were collected fromtuberculosis patients in Xinjiang and 60 Mycobacterium tuberculosis strains were isolated from the samples(28 drug susecptible strains,32 strains of inonizaid resistance or multidrugre sistance including inoniazid).Genomic DNA was extracted form Mycobacteriumtube rculosis isolates and standard strain H3TRV.The KatG gene was amplified with PCR and KatG gene mutation was detected with single strand conformation polymorphism(SSCP)and sequencing.Results The results of PCR-SSCP of 28 susceptive strains were the same with that of H37RV.KatG gene was amplified from 32 drugresistance strains succe ssfully.There were 11 cases had single pointmutation in KatGgene with amutation rate of 34.37%.Conclusion The INH resistance rate of Mycolacterium tuberculosis strains isolated from Xinjiang is among the highest in China.The KatG gene mutation is involved in INH rsistance of Mycobacterium tubeculosis.