Abstract: In this study, PCR primers were designed base on the known genes in wheat and its relatives to isolate α-gliadin genes from Ae. sharonensis, one species of the Sitopsis section of the genus Aegilops, which was traditionally considered as the B-genome donor of tetraploid and hexaploid wheat. Three novel α-gliadin genes were obtained. Analyses of the nucleotide and deduced amino acids of the obtained genes indicated that they shared the high sequence identities and similar primary structures to the known α-gliadin genes. Further more, the extensive variations were found. A phylogenic analysis based on the multigene alignment of the deduced amino acid sequences showed that the α-gliadin genes derived from Ae. sharonensis and Ae. speltoides were significantly distinguished from those of diploid A and D genome progenitors of wheat, but clustered closed to some genes from tetra- and hexaploid wheats. Moreover, genes derived from Ae. sharonensis were more closed to wheat than from Ae. speltoides. This result suggested that the origin and formation of wheat B genome might be polyphyletic.