The laminate structure was applied to improve the mechanical properties of Mg-8.0Gd-3.0Y-0.5Zr alloys.Two types of laminate structures only with different distribution positions of fine grains were produced by friction-stir processing.Results show that the trilayer structure sample exhibits an excellent strengthductility synergy compared to the homogenous structure and bilayer structure.The enhanced mechanical properties are resulted from the hetero-deformation induced (HDI) stress strengthening and strain hardening which would be enhanced by increasing the quantity of interface.These observations suggest a crucial role of the number of interfaces in designing the laminate structure.