Al alloy sheet with a composition of Al–5.5Mg–0.3Cu was successfully fabricated using a combined technique of twin-roll strip casting and asymmetric rolling. The Al sheet produced in this study exhibited an excellent formability (r¯=1.0, Δr=0.16) and mechanical properties (σ TS ∼305MPa, ɛ∼33%), far exceeding those shown by the commercially available Al sheets. The structural origin of these properties, especially the improved formability, was elucidated by analyzing the evolution of textures associated with strip casting and subsequent thermo-mechanical treatment.