The bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae is the most devastating disease that prevalent in all the rice growing areas of the world. The pathogen produced small water-soaked lesions, which later turn to yellowish white colour, elongated circular to quite uneven lesions. The most important factors for disease development are temperature, relative humidity, rainfall, sunshine hours and number of rainy days. Flooding and water logging conditions, not only cause wounds that hasten up infection and enhance severity of the BLB but also aid in the dissemination of the plant pathogen. BLB pathogen is highly variable in nature and continuous monitoring of its virulence profile is very important for breeding durable resistant varieties. Therefore, monitoring of pathotypes is helpful in evaluating the distribution patterns and composition of the dominant pathotypes. Various rice lines have resistance against Xoo under under epiphytotic conditions. RP 633-519-1-3-8-1, RP2151-173-1-8, BBL 180-5-1-4-1, IR 13610-72-2-2E-P1, IR 22082-41-2, C 702015 and IR 50400-64-1-2-2-2 are some superior line used in breeding programme for developing resistant.