Mg and its alloys are regarded as potential candidates to replace steel and other heavier materials in some applications due to low density and high specific strength. However, the application of Mg alloys is limited because of their low strength, poor formability and corrosion resistance. Grain refinement and Mg-Al composite have been applied successfully to improve the strength and formability of Mg alloys. The accumulative roll bonding (ARB) is one kind of severe plastic deformation process which can produce bulk ultra-fine grained metallic materials. In the present work, the ultra-fine grained alternative Mg/Al multilayered composite sheets were fabricated at room temperature by ARB process using commercial pure Mg and AA1050 Al sheets up to 3 cyc. Some of Mg/Al sheets after 3 cyc ARB were annealed at 200 ℃ for 15, 60 and 90 min, respectively. The microstructure of ARBed sheets were invesgated by OM and SEM. The global texture evolution of these ARBed sheets were measured by neutron diffraction. It is found that the grains in both Mg and Al layers are refined gradually with the increase of ARB cycles. Although the grains in the Mg layers didn't grow up obviously after annealing at 200 ℃ for different times, the homogeneity of the microstructure was improved. The Mg layers of ARBed sheets showed typical rolling texture which enhanced with the increase cycle of ARB process up to 2 cyc and decreased sligthly after 3 cyc. The Al layers exhibited a combination texture types of rolling and shear texture, including Copper, S, Brass and rotated cube (RC) texture components. After 200 ℃ annealing, the Mg layers remained typical rolling texture component and it's intensity enhanced significantly after 15 min annealing and kept stable during the following annealing processing. The Al layers maintained a combination of rolling and shear texture components, the intensity of rolling components became stronger after 15 min annealing, then decreased after 60 and 90 min annealing. The yield strength and tensile strength were improved while the ARB cycle increased.