Abstract:The 2270 of rice germplasm resources from International Rice Bacterial Blight Nursery (IRBBN) were evaluated against rice bacterial blight disease in South China. The identified results against the pathotype Ⅳ which was the most predominant indicated that 500 varieties (22.03%) were highly resistant (scale 1), 617 varieties (27.18%) resistant (scale 3), 355 varieties (15.64%) moderately susceptible (scale 5),373 varieties (16.43%) susceptible (scale 7) and 425 varieties (18.72%) highly susceptible (scale 9) among the 2270 of rice germplasm resources. Against the pathotype Ⅴ which was the most highly virulent in South China, 131 varieties (8.23%) were highly resistant, 322 varieties (20.23%) resistant, 292 varieties (18.34%) moderately susceptible, 422 varieties (26.50%) susceptible and 425 varieties (26.70%) highly susceptible, respectively. Among which, 411 varieties (25.82%) showed resistance to both of the pathotype Ⅳ and Ⅴ. Some germplasm resources, such as BG1222, IRBB5, IRBB7 and IRBB203 with excellent agronomic characters and high resistance were screened out. A new bacterial blight resistance gene from BG1222 was identified according to genetic analysis, and the resistance gene was mapped on chromosome 1. Some resistant germplasm resources were selected for rice resistance breeding program, and numbers of varieties with high yield and good quality were bred successfully. Thereinto, the cultivar Baixiangzhan originated from IRBB5 (xa5) was the first released rice variety against virulent pathotype Ⅴ in South China.