Bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most destructive diseases in rice fields. This study aims at isolating and identifying antagonistic soil bacteria to bio-control this disease. Among 124 bacterial isolates obtained from rice fields of Can Tho City, CĐ15 and OM34 exhibited strong antagonistic effects against the pathogen. Seed soaking with suspensions of the two isolates did not give any observable adverse effects on rice seed germination but induced the development of germinated seeds. Under greenhouse conditions, seed soaking with suspension of isolate OM34 (10⁷ CFU/ml) showed strong disease-reducing effects on bacterial leaf blight until 15 days after pathogen inoculation. Its effects involved the production of siderophores which are iron-chelating compounds. OM34 was identified as Paenibacillus thailandensis based on 16S rRNA sequencing combined with physiological and biochemical characterizations.