Objective：To detect the mutation of isoniazid resistance gene inhA-15（C-T） in drug-resistant tuberculosis strains by genechip technology，and to provide guidance for the treatment of drug-resistant tuberculosis patients. Method：From January 1，2014 to December 31，2016，patients with smear positive tuberculosis were continuously enrolled in TB designated hospitals in Lianyungang city of Jiangsu Province. The wild type and mutant type gene rpoB and wild type and mutant type of katG and inhA were detected by gene chip technique. Based on the results of traditional susceptibility test，the mutation frequency of related resistance loci，especially the mutation of isoniazid resistance related gene inhA-15（C-T），was analyzed in different drug-resistant strains. Results：A total of 1 356 patients with pulmonary tuberculosis were included in the final analysis. Through the detection of genechip technology，22（12.2%）strains had a single mutation at inhA gene mutation without katG mutation，Among them，3 cases of multidrug-resistant tuberculosis（MDR-TB） accounted for 15.4%，1 case of early extensive drug resistant tuberculosis（pre-XDR-TB） accounted for 7.7%，and 3 cases of extensively drug-resistant（XDR-TB） strains accounted for 23.1%. There were 32 cases（17.7%） had inhA gene mutation and / or katG gene mutation，of which 12（23.1%） were in MDR-TB，3（23.1%） were in pre-XDR-TB，and 3（23.1%） were in XDR-TB. Conclusion：More than 10% drug-resistant TB patients have a single mutation at the inhA-15 locus，indicating that large doses of isoniazid can be used to treat these drug-resistant patients. Although ethionamide（protionamide） had been widely used in the treatment of MDR-TB patients，almost 20% of drug resistant patients were resistant to these two drugs. The application of genechip has specifically reported gene mutations in drug-resistant tuberculosis patients，which will have some guiding effect on clinical treatment.