Abstract: Objective To evaluate the clinical value of gene chip on rapidly detecting isoniazid (INH)-resis-tant Mycobacterium tuberculosis (Mtb) clinical isolates in Suzhou city.Methods The sputum samples were collected from TB patients in the Affiliated Hospital of Infectious Diseases of Soochow University. Mtb isolates were performed the conventional drug susceptibility testing on the Lwenstein-Jensen culture medium. 21 INH-resistant and 21 INH-sensitive strains were randomly selected, and then detected genes katG315 and inhA-15 by gene chip. The PCR fragments of katG gene including katG315 from 18 samples tested by gene chip were sequencing. The results of DNA chip were respectively compared with traditional drug susceptibility test and DNA sequencing.Results Using the traditional drug susceptibility testing and DNA sequencing as the controls, the accurate rates of gene chip for detecting INH resistance and katG 315 point mutation were 73.8% (31/42) and 88.9% (16/18), respectively.Conclusion INH resistance in Mtb was mainly induced by gene mutations at katG 315 and inhA-15 in Suzhou city. It can be rapidly, accurately detected by gene chip.