In order to understand the molecular mechanism of tartary buckwheat against bacterial blight， we isolated the transcription factor gene FtEIN3 in Chuanqiao 1， a representative variety of tartary buckwheat.The FtEIN3 contains the CDS sequence length of 1623 bp， encoding 540 amino acids. The secondary structure of FtEIN3 protein was composed of α-helix （33.52%）， extended chain （6.67%）， β-fold （2.41%） and irregular coil （57.41%）. Phylogenetic tree indicated that FtEIN3 protein was closely related to GhEIN3 and DzEIN3 protein. Five different EIN3 sequence haplotypes were detected in 108 tartary buckwheat germplasm， and out of them Hap3 was an elite haplotype. qRT-PCR revealed that the expression of FtEIN3 gene in tartary buckwheat was induced by Rhizoctonia solani. The FtEIN3 gene in tartary buckwheat was localized in the nucleus under confocal laser microscopy. To further verify the function of FtEIN3 gene， FtEIN3 transgenic Arabidopsis thaliana were constructed and their resistance to blip disease was analyzed. The results showed that overexpression of FtEIN3 gene significantly improved the resistance of transgenic Arabidopsis thaliana to bacterial blight compared with the wild type. These results proved that FtEIN3 gene was involved in the defense process of tartary buckwheat against bacterial blight， and laid a foundation for further research on the molecular mechanism of FtEIN3 regulation of tartary buckwheat resistance to blight.