Effects of deformation temperature and strain rate on the high temperature flow stress and microstructure of the Mg-5Li-11Gd-1Zn-0.5Zr alloy were studied by using Gleeble-3500 thermal simulator at 250-400 ℃ and strain rate of 10-3-1 s-1.The results show that the steady-state flow stress of the alloy decreases with the increase of deformation temperature and increases with the increase of strain rate.With the increase of deformation temperature,the long period stacking ordered(LPSO)phase kinks or refines,and the degree of dynamic recrystallization of the alloy increases gradually.With the increase of strain rate,the LPSO phase distribution is more uniform and the grain size of the alloy increases gradually.The thermal deformation activation energy calculated according to the Arrhenius theory is 142.65 kJ/mol.The instability area and safe area are obtained from the hot processing map,the easy processing area of the alloy is in the range of the deformation temperature of 350-400 ℃ and strain rate of 0.011-0.45 s-1,where the granular LPSO phase can promote dynamic recrystallization.