The molecular features of Pseudomonas syringae pv. actinidiae strains isolated in Korea were compared with strains isolated in Japan and Italy. Sequencing of eight P. syringae pv. actinidiae and three P. syringae pv. theae strains revealed a total of 44 single nucleotide polymorphisms across 4,818 bp of the concatenated alignment of nine genes. A multiplex PCR assay was developed for the detection of P. syringae pv. actinidiae and for the specific detection of recent haplotype strains other than strains isolated since the 1980s in Korea. The primer pair, designated as TacF and TacR, specifically amplified a 545-bp fragment with the genomic DNA of new haplotype of P. syringae pv. actinidiae strains. A multiplex PCR conducted with the TacF/TacR primer pair and the universal primer pair for all P. syringae pv. actinidiae strains can be simultaneously applied for the detection of P. syringae pv. actinidiae and for the differentiation of new haplotype strains.