The aim of this study was to test the performance of a new reagent kit Tosoh TRCRapid M.TB using by transcription-reverse transcription concerted reaction(TRC) for detection of Mycobacterium tuberculosis complex (MTC) by comparing both its sensitivity and specificity for detecting MTC with those of Roche COBAS AMPLICOR Mycobacterium assay using polymerase chain reaction (PCR) and comparing with culture. TRC is a novel method, that is rapid and provides real-time monitoring of the isothermal sequence of RNA amplification without any post-amplification procedure, and the resulting detection time was about 30 min. A total of 157 clinical samples from patients were tested. Of the 74 MTC culture-positive samples, TRC was positive in 59(sensitivity, 80%), whereas PCR was positive in 47(sensitivity, 63%). The 26 samples that were positive for Mycobacteria other than tuberculosis (MOTT) were negative by TRCRapid M.TB assay, and the 50 samples that were negative for smear, culture and Roche PCR were also negative by TRCRapid M.TB. The percent agreement between Tosoh TRCRapid M.TB and Roche COBAS AMPLICOR was 90% (142 of 157 samples). These results indicate that Tosoh TRCRapid M.TB may be more useful than Roche COBAS AMPLICOR for detecting MTC because of its higher sensitivity and shorter detection time.