Recently, it was reported that Cu-Al alloys of low stacking fault energy (SFE) processed by severe plastic deformation show excellent tensile properties due to TWIP (Twinning induced Plasticity) phenomenon. In this study, Cu-15at% Al sheets were heavily processed by conventional multi-pass cold rolling up to 90% in reduction in thickness without annealing. In order to reveal the change in mechanical properties and the microstructure evolution, tensile test, hardness test, optical microscopy (OM) and electron backscattering diffraction (EBSD) analysis were performed. Deformation twinning due to low SFE is observed even in the case of low reduction in thickness. As the reduction increases, grains are refined by intersections of shear bands. It is found that the balance of strength and elongation of the processed sheets is comparable to those by severe plastic deformation followed by annealing in literature.