To improve comprehensive mechanical properties of Mg-Li alloy, alternative α/β Mg-Li composite sheets with a bimodalgrainedstructure were prepared by accumulative roll bonding (ARB). The microstructure, texture, mechanical propertiesand strain hardening behavior of the alternative α/β Mg-Li composite sheets were studied. The bimodal grain structure,with ultrafine grains (about 0.79 μm) in the α alloy and coarse grains (about 53.28 μm) in the β alloy, can be observed in thecomposite sheet. The dominant texture of α-Mg and β-Li alloys is {0002} basal texture and {110} texture, respectively. Inthe α alloy, the basal texture decreases gradually with the increase of ARB pass, and the non-basal texture is formed in thesheet processed by 5-pass ARB. The dislocation density of the composite sheet gradually increases and approaches saturationafter 3-pass ARB process due to the balance between dislocation accumulation in the ARB process and dislocationannihilation in dynamic recovery. The sheet processed by 3-pass ARB has the preferable strength and plasticity, with yieldstrength, ultimate tensile strength, elongation of 204 MPa, 216 MPa, 22.73%, respectively. Compared with the as-annealedalloys before ARB, the strain hardening rate of the ARB composite sheets increases gradually at low stress (stage II). Mg-Lisheets produced by ARB process remain a high plasticity because of the longer softening stage (stage III), which is mainlycontributed to the synergistic effect of the bimodal grain structure and the activation of non-basal texture.