To investigate functions of flgKpcc gene in Pectobacterium carotovorum subsp. carotovorum (P. c. c).The gene knock-out mutant deltaflgKpcc and complemented strain deltaflgKpcc-KH were generated by biparental mating and their phenotypes including cell morphology, motility, pathogenic factors, and pathogenicity were investigated.Non-flagellum, cell precipitation in the culture and significantly attenuated motility on 0.3% semisolid medium were observed in deltaflgKpcc compared to Pectobacterium carotovorum subsp. carotovorum S1. In addition, significant decrease in cellulase and protease activity, biofilm formation, and pathogenicity on host plant were found in deltaflgKpcc. While there were no apparent difference in growth rate in vitro, deltaflgKpcc-KH, the complementation strain, restored the phenotype of deltaflgKpcc to the wild type level.The gen of flgKpcc not only influences the cell motility, but also pathogenic factors to lead to the decreased pathogenicity in Pectobacterium carotovorum subsp. Carotovorum.