A bacterial blight resistance gene, Xa1, confers a high level of specific resistance to race 1 strains of Xoo in Japan. The molecular mechanism of expression regulation of Xa1 is obscure, though it was cloned and its expression and function was studied. In this paper, we analyzed the temporal and spatial expression and different hormones inducibility of Xa1 promoter, in the T1 generation of transgenic rice by fusing Xa1 promoter with a reporter gene GUS. The results indicated that GUS expression driven by Xa1 promoter in roots was higher than in stems and leaves, especially strong in filling post of roots. GUS expression was increased significantly treated by MeJA, and increased slightly by SA and ABA. These results suggested that the resistance of Xa1 was related to its tissue-specific expression in filling post. MeJA played a critical role in activity regulation of Xa1 promoter.