Abstract:A multiplex real-time PCR was developed to detect ctxA of Vibrio cholerae, gyrB and tdh of Vibrio parahaemolyticus simultaneously. The multiplex real-time PCR were evalidated by detection for the three genes in 47 toxigenic V. cholerae O1 and O139 strains (ctxA+; O1=3, O139=44), 25 non-toxigenic V. cholerae strains (ctxA-; O1=12, O139=6, non-O1 and non-O139=7), 116 V. parahaemolyticus strains with or without tdh (73 or 43) and 9 other bacteria strains. The specificity and sensitivity of the multiplex real-time PCR in detection for the ctxA and the tdh genes in the strains tested were both 100.0%, compared to the results by routine PCRs. In the detection for V. parahaemolyticus specific gyrB using the multiplex real-time PCR, all of 116 V. parahaemolyticus strains were positive, and 9 other strains and 72 V. cholerae strains were all negative. The multiplex real-time PCR is a sensitive, specific and quick assay not only for detecting virulence genes of V. cholerae and V. parahaemolyticus but also for identifying V. parahaemolyticus at species level. In addition, two real-time PCRs for detection of V. parahaemolyticus virulence genes trh1 and trh2 were also developed.