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High-temperature compressive deformation behaviors of Mg-6Zn-1.5Y-0.5Ce-0.4Zr alloy were investigated at temperatures and strain rates ranging from 523 to 673 K and from 0.001 to 1 s-1,respectively.The studied alloy was mainly composed of α-Mg,Mg3Zn6Y(I phase),Mg-Zn-Ce and Mg3Zn3Y2(W phase).The constitutive equation of Mg alloy was obtained,and the apparent activation energy(Q)was determined as 200.44 kJ/mol,indicating that rare earth phase increases the difficulty of deformation.The work hardening involves three stages:(1)linear hardening stage;(2)strain hardening stage;and(3)softening and steady-state stage.During these three stages,the dislocation aggregation and tangling,dynamic recovery and recrystallization occur sequentially.To characterize the dynamic recrystallization(DRX)volume fraction,the DRX kinetics was investigated using the Avrami-type equation.The deformation mechanism of magnesium alloy under different Zener-Hollomon parameter(Z)value conditions was also studied.At high Z values and intermediate conditions,dislocations rapidly generate and pile up in the alloy.Recrystallization is hardly seen at this time.At low Z condition,the DRX occurs in the alloy.