The resistance to bacterial leaf blight of Conventional varieties(chodongi, Yongcheon etc.) cultivated from 1920 to 1956 in Korea were tested by means of 5 pathotypes of causal organism Xanthomonas oryzase (Uyeda et lshiyama) DOWSON. The results of this test are : 1. Among 74 varieties, 69 varieties including "Chodongji, Yongcheon, Aedhal, Yongsang, Daegu, Mitdhari, pungok, etc" belong to the Kinmaze group that is highly susceptible to this disease. 2. 3 varieties : Heukbal, Doipnam, Whangphan belong to the Kogyoku group. 3. 2 varieties : Narngok, Gangbukdo, show unknown reaciton to differential varieties. 4. In 69 varieties belonging to the Kinmaze group 99.5% of the plants were infected by bacterial group Ⅰ. 99.6% in bacterial group Ⅱ. 100% in group Ⅲ, 99.7% in group Ⅳ, and 99.8% in group Ⅴ. 5. In 3 varieties belong to Kyogyoku group, 1.7% of the plants were infected in bacterial group Ⅰ. 98.8% in group Ⅱ, 100% in group Ⅲ, Ⅳ and 1.4% in group Ⅴ.