Abstract: Objective To evaluate the value of MTBDR-Plus assay on the detection of rifampin (RIF) and isoniazid (INH) resistance in M. tuberculosis clinical isolates. Method 197 M. tuberculosis clinical isolates were collected to do conventional drug susceptibility testing and MTBDR-PluvS assay. The sensitivity and specificity of MTBDR-Plus assay were analyzed and compared with conventional drug sensitivity testing. Results The sensitivities of MTBDR-Plus assay for detecting RIF and INH were 88. 6% and 79.3%，respectively. Their specificity were 98. 8% and 98.8%，respectively. Conclusion MTBDR-Plus assay is a rapid and reliable method with high sensitivity and specificity.

Key words: Myrobarterium tuberculosis , rifampin, isoniazid, microbial sensitivity tests