Abstract: Objective To develop a new genechip for rapid detection of multidrug resistant Myco bacterium tuberculosis(M TB) to streptomy cin(SM),ethamtubol(EMB),rifampin(RFP) and/or isoniazid(INH).Methods The resistances of 300 MTB clinical isolates to SM,EMB,RFP and INH were detected with gene chip.Results Among the 300 MTB clinical isolates,188 isolate swere SM sensitive,112 were SM resistant with most of mutation of aag to agg on rpsL 43 and 88; 251 isolates were EM B sensitive and 49 were EMB resistant with the most of mutation of atg to gtg on embB 306; 251 isolates were RFP sensitive,49 resistant,and the mutation were mostly aag to gag on ropB 516; 210 isolates were INH sensitive,90 resistant,and the mutation were mostly gtg to gag on KatG 315.The sensitivity and specificity of the four antibiotic resistance were 81.1% and 99%,60.0% and 100%,72.0% and 98%,75.0% and 99%,respectively.For the isolates with different results by gene chip and conventional method,gene sequencing was applied,and the results showed that genechip for mutation detection had high specificity.Conclusion The detection for SM,EMB,RFP and INH resistance of MT B by combined gene chip is rapid and specific and could be applied to fast clinic screening.