Two soft rot causing bacterial genera Pectobacterium sp. and Dickeya sp. belong to the family Entrobacteriaceae, are important plant pathogens which lead to major losses in field crops, vegetables and ornamental plants countywide including Isfahan province. In spite of their ability to induce soft rot in a wide rang of plants as a common symptom, the members of these two bacterial genea are significantly divergent in terms of physiological, pathological and ecological characteristics.Therfore, preision studies is required for identification and differentiation of Pectobacterium and Dickeya species causing plants soft rot and their abundancy in different geographical regions. Due to widespread occurrence of plant soft rot diseases in Isfahan province, in this study attempt was mad to determine the relative abundance of Pectobacterium and Dickeya species and suecies in the regin. To do this, the plants, particulary potatoes showing soft rot and black leg symptoms were collected from the fields of Isfahan province and some restricted area of Takistan in Qazvin, Eghlid in Fars and Jourhgan in Hamedan province. All of the causative bacteria isolated from the soft rotted samples were negative in Gram staining, Oxidase activity, starch and tween80 hydrolysis while positive in nitrate reduction, gelatin utilization and potato rot test. Based on physiological characteristics and rep-PCR typing using Box IR and ERIC1/ ERIC2 primers, all the isolates were clustered in two heterogenous group Pectobacterium sp. (groupI) and Dickeya sp. (groupII). The results of confirmatory biochemical tests and amplification of the target DNA of the isolated in PCR with species specific primers and nucleotide sequencing revealed that among 64 isolates in groupI, P . carotovorum su. carotovorum(33 isolates) is the most abundant suecies than P . carotovorum su. brasiliensis (17 isolates) and P . pamentieri (14 isolates). All these bacteria are common in temperate, tropical and sub-tropical regions, hence their presence was expected in Isfahan rgin. P . atrosepticum as the cauaul agent of potato blackleg adapted in European cool and wet climate was not isolated from the samples. The biochemical and molecular feautures of 14 isolates from group II lead to identification of Dickeya solani and D . dadantii from soft rotted potatoes and onions. However the remaining species have yet to be identified denfinitely. According to the results, it can be concluded that several species and suecies of Pectobascterium sp. and Dickeya sp. are involved in soft rot diseases of various crops in the region, of which P . cartovorum susp. carotovorum is the most abundant species. Key words: Pectobacterium sp., Dickeya sp., Soft rot disease.