The details of structure modification on alpha(2/gamma) interface induced by deformation in a hot-deformed Ti-45Al-10Nb alloy were investigated by conventional and high-resolution transmission electron microscopy. A new type of dislocation ledge containing 1/3[111] partials was identified. The Burgers vectors of these dislocation ledges were determined to be 1/2[110] or 1/2[101]. The formation mechanism of this new type of dislocation ledge is discussed. Also, two types of hot deformation induced alpha(2/gamma) interfaces, coherent interfaces with high density of ledges and misoriented semi-coherent alpha(2/gamma) interfacial boundaries were observed. For the misoriented semi-coherent alpha(2 gamma) interfaces, the density of dislocation ledges in these interfaces increases with the misoriented angle between the (111)(gamma) and (0001)(alpha 2) planes, and 1/3[111] partial dislocations were involved in all the dislocation ledges. The formation mechanism of these deformation-induced alpha(2/gamma) interfaces were discussed related to the role of alpha(2/gamma) interfaces adjusting the deformation as a dislocation sink absorbing the slipping dislocations in the gamma phase. Moreover, misoriented semi-coherent alpha(2/gamma) interface related deformation twinning and structure transformation induced by deformation were analyzed and discussed related to the role of alpha(2/gamma) interfaces as a dislocation source during deformation.