Three isolates out of 18 isolates of Erwinia carotovora subsp.  carotovora were isolated from diseased potato tubers showing soft rot symptoms, and chosen to assess their virulence and to differentiate them on the basis of RAPD-PCR technique and protein SDS-PAGE analysis. Nine cultivars of potato differed in their susceptibility to the three tested isolates of Ecc, which varied in their virulence on potato tubers of different cultivars where isolate A was the most virulent followed by isolate B whereas, isolate C was the least virulent one. Five primers i.e: Bic 1, A9B4, A9A10 , BAQ and BAR were chosen based on cost consideration and their capacity to discriminate between the bacterial isolates. All the five primers used showed different levels of polymorphism and revealed clear differences among the three isolates of Ecc. Distinguish differences were detected in the number and molecular weights (M.W) of the extracted protein bands among more virulent and less virulent isolates of Ecc. On the basis of RAPD-PCR technique and SDS-PAGE analysis, our results indicated that there 
 
are two main groups. Group 1 include one sample represent isolate C, however, group 2 include two subgroups represent isolate A and B, that are similar at the DNA level.