For the genetic differentiation of Pseudomonas syringae pathovar tomato, a total of 51 P. syringae pv. strains infecting 33 different host plants were analyzed using repetitive element PCR(REP-PCR) and universal rice primer PCR(URP-PCR). The entire DNA fingerprint profiles were analyzed using unweighted pair-group method with arithmetic averages (UPGMA). The 51 P. syringae pv. strains could be divided into five clusters based on 65% similarity by Rep-PCR using BOX, ERIC, and REP primers. P. syringe pv. tomato cluster was well separated from other 31 P. syringae pathovars. P. syringae pv. tomato cluster included only P. syringae pv. maculicola and P. syringae pv. tomato. P. syringae pv. tomato strains could be divided into two genetic groups. Meanwhile, the Pseudomonas pv. strains could be divided into four clusters based on 63% similarity by URP-PCR using 2F, 9F, and 17R primers. P. syringae pv. tomato cluster was also well separated from 30 other P. syringae pathovars. In this case, P. syringae pv. tomato cluster included P. syringae pv. maculicola, P. syringae pv. berberidi, and P. syringae pv. tomato. P. syringae pv. tomato strains was also separated into two genetic groups by URP-PCR analysis. Overall, our work revealed that P. syringae pv. tomato can be genetically differentiated from other P. syringae pathovars by the DNA fingerprint profiles of REP-PCR and URP-PCR. We first report that there are two genetically diverged groups in P. syringae pv. tomato strains.