To study the effect of probenazole on the induced systemic resistance mechanism of rice-bacterial interaction, a proteomic approach was applied. Oryza sativa cv. Java 14 seedlings were treated with probenazole, followed by inoculation with compatible (Xo7435) and incompatible (T7174) races of Xanthomonas oryzae pv. oryzae. Cytosolic proteins were fractionated from leaf blades, separated by two-dimensional polyacrylamide gel electrophoresis. Pathogenesisrelated protein 5 (PR5) was significantly induced with probenazole treatment followed by inoculation with T7174 or Xo7435. The sense PR5 transgenic rice plants were more highly resistant than the susceptible vector control against Xo7435. These results indicate that probenazole strongly induces PR5 in the interaction between rice and X. oryzae pv. oryzae, and might be involved in the resistance mechanism of rice against bacterial blight.