Abstract: The bacteriocin productivity of Xanthomonas camperstris pv.oryzicola, Xanthomonas camperstris pv.oryzae and Xanthomonas camperstris pv.citri, that totally have 92 strains from different places, was detected by double-layer medium method.The results showed that 34 strains produced bacteriocin, occupies 37% of the total strains.Among the bacteriocin-producing strains, crossinhibition reaction was observed in 4 different species.The diameter of inhibition zones varied from 2-6mm.The inhibition ability of bacteriocin-producing strains to the same species was better than that to different species.