Abstract: Abstract： Fusarium oxysporum f.sp.cubense(Foc) is the most destructive pest of bananas in the world. Two pairs of primers PR1/PR2 and ST1/ST2 were developed to identify the Foc. The primers PR1/PR2 and ST1/ST2 could produce bands for race1 and race4 of Foc. At the same time, the parameters of PCR were optimized and sensitivity were tested. The optimized conditions were an annealing at 56 ℃. The minimum amount of DNA of Foc could be detected was as low as 20 ng. It demonstrates that duplex PCR approach will provided an accurate and effective method for quick detection of Foc.