Rice bacterial blight is one of the major bacterial diseases of rice production. Rice bacterial blight resistance materials developed from wild rice may increase rice resistance resource. Xa21 gene in Yunnan wild rice was detected by inoculation identification and PCR marker analysis. The results shown Yunnan wild rice was excellently resistant to PX099A and Y8, especially, Oryza meyeriana was immunity. O. meyeriana, O. rufipogon and cultivated rice have Xa21 homologous fragment gene. It will lay the foundation for finding out new bacterial blight resistance resource and exploring new resistance gene.