Despite the constant stacking fault energy in Cu alloy, the addition of Mn promotes a structural evolution of copper-manganese (Cu–Mn) alloy that substantially differs from that of pure Cu during rolling. This advantage is leading to Cu–Mn alloy gradually replacing pure Cu as a sputtering target for fabricating integrated circuits because of its unique characteristic of a self-forming diffusion layer. Thus, the deformation texture evolution in a Cu-3 at%Mn alloy subjected to unidirectional rolling with different reductions was investigated. The spatial arrangement of the crystallographic texture and orientations of 22%, 36%, 50%, 61.3% and 70% rolled samples prepared in quasi in situ continuous rolling was analyzed using electron-backscatter diffraction (EBSD) combined with several deformation models, such as a modified materials-dependent Taylor model. Among all the deformations, several representative deformations—specifically, 50%, 77% and 95%—were selected to demonstrate macrotexture development by x-ray diffraction analysis. The results show that the dominant texture evolves from a Copper texture ({112} ) to a Brass texture ({110} ) accompanying deformation.