In this study,a construct-specific real-time PCR method for quantitative detection of genetically modified maize line MIR604 was established with primers and probes designed based on vector sequence of MIR604 under optimized reaction system and thermal cycling condition.By using the established method,six non-genetically modified crops,genetically modified maize line MIR604 and other non-target genetically modified crops were detected.According to the results,fluorescence signal could be detected in genomic DNA of MIR604,but other non-genetically modified crops and non-target genetically modified crops exhibited no fluorescence signal of MIR604 molecular fragment.Certified reference materials containing 1% MIR604 were detected with the established method and the results indicated that the average relative content in the test samples was 1.05%.The sensitivity analysis results indicated that MIR604 nucleic acid fragment with at least five copies could be detected with the established method.In conclusion,the construct-specific real-time PCR method for quantitative detection of genetically modified maize line MIR604 is of high specificity,accuracy and sensitivity,which provides technical support for safety supervision of genetically modified organisms in China. In this study, a construct-specific real-time PCR method for quantitative detection of genetically modified maize line MIR 604 was established with primers and probes designed based on vector sequence of MIR 604 under optimized reaction system and thermal cycling condition. BY using the established method, six non-genetically modified crops, genetically modified maize line MIR604 and other non-target genetically modified crops were detected. According to the results, fluorescence signal could be detected in genomic DNA of MIR604, but other non-genetically modified crops and non-target genetically modified crops exhibited no fluorescence signal of MIR604 molecular fragment. Certified reference materials containing 1% MIR604 were detected with the established method and the results indicated that the average relative content in the test samples was 1.05%. sensitivity analysis results indicated that MIR604 nucleic acid fragment with at least five copies could be detected with the established met hod.In conclusion, the construct-specific real-time PCR method for quantitative detection of genetically modified maize line MIR604 is of high specificity, accuracy and sensitivity, which provides technical support for safety supervision of genetically modified organisms in China.