Abstract: In order to take effective measures to control tobacco bacterial wilt in Henan Province, the pathogenicity and genetic diversity of Ralstonia solanacearum from tobacco in Luoshan, Queshan and Suiping counties of Henan Province were investigated. The results showed that all the isolates could be divided into three pathogenic types including strong, medium and week pathogenicity by artificial inoculation. Also, the Ralstonia solanacearum strains from different hosts showed significant difference in pathogenicity. Eight primers which were screened from 100 primers were used in RAPD analysis of Ralstonia solanacearum Isolates. A total of 720 bands were obtained and 88.9% of them were polymorphic. Based on clustering and similarity analysis, the tested isolates fell into two groups and the genetic similarity among different strains was from 0.49 to 1.00. Moreover, the genetic similarity might be related to different geographical origin. In summary, the Ralstonia solanacearum isolates infecting tobacco in southern Henan Province showed obvious differentiation of pathogenicity with abundant genetic diversity.