Abstract:Forty-three Ralstonia solanacearum strains collected from 11 provinces or cities in China and 4 strains obtained from other countries were amplified by PCR using 15 random primers. A DNA fragment specific for all tested strains of R.solanacearum was screened out according to RAPD analysis. A pair of specific primers was constructed based on the sequencing results. The PCR amplification produced expected 773 bp sequence products only from R. solanacearum strains, but not from other bacterial pathogens of the potato. Using the PCR amplification technique, the 773 bp fragment was obtained from bacterial wilt diseased potato tubers. This technique provides a basis to develop a more effective detection method for the infection of R. solanacearum.