ZE10 magnesium alloy was subjected to equal-channel angular pressing(ECAP) up to 12 passes in a die with an angle of 120° between the two channels at 250-300°C.An inhomogeneous microstructure of bimodal grains including fine grains of 1-2 μm as well as coarse grains of about 20 μm was obtained after the initial 1-4 ECAP passes.The grain size became increasingly homogeneous with further ECAP processing and the grains were significantly refined to 1-2 μm after 8 passes and further refined to 0.5-1 μm after 12 passes.The alloy’s yield strength changed slightly but the ductility improved greatly initially up to 4-6 passes corresponding to the bimodal grain microstructure.And after the subsequent pressing of more than 8 passes,the tensile strength including yield strength improved while the elongation decreased gradually. ZE10 magnesium alloy was subjected to equal-channel angular pressing (ECAP) up to 12 passes in a die with an angle of 120 ° between the two channels at 250-300 ° C. An inhomogeneous microstructure of bimodal grains including fine grains of 1- 2 μm as well as coarse grains of about 20 μm was obtained after the initial 1-4 ECAP passes. Grain size has been homogeneous with further ECAP processing and the grains were significantly refined to 1-2 μm after 8 passes and further refined to 0.5-1 μm after 12 passes. The alloy’s yield strength changed slightly but the ductility improved greatly initially up to 4-6 passes corresponding to the bimodal grain microstructure. And after the subsequent pressing of more than 8 passes, the tensile strength including yield strength improved while the elongation decreased gradually.