The effect of induced resistance against angular leaf spot of cucumber (P. syringae pv. lachrymans) following application of Pantoea spp. strain HB-22 on cucumber leaves was investigated. Cucumber roots were treated with HB-22 at 2 and 3 weeks after planting. Control plants received broth culture without bacteria. Pathogen, P. syringae pv. Lachrymans suspension was sprayed on cucumber leaves 4 weeks after planting. Plant fresh weight was the highest in HB-22 treated plant, followed by control, HB-22 + P. syringae pv. lachrymans, and P. syringae pv. lachrymans treated plant where HB-22 reduced disease severity compared to control plants at 10 days after infection. The activities of Pathogenesis-Related (PR) proteins, such as â-1,3-glucanase and chitinase had no significant difference among all treatments until 3 days and then increased in P. syringae pv. lachrymans treated plant leaves. However, the increase of PR proteins by P. syringae pv. lachrymans infection was alleviated in HB-22 treated plant. The PR proteins levels were much higher in control plant than in HB-22 treated plant, although control plants had severer damage after pathogen infection. Therefore, increases of PR proteins activities do not seem to be a close relationship with plant protection after pathogen infection. It seems to be more relative to plant response or disease severity in this study.