The effect of rare earth element erbium on the thermal compression deformation behavior of the ZK60 magnesium alloy was studied by Gleeble-1500D thermal simulator. Constitutive equation of thermal compression of ZK60 and ZK60-1.0Er magnesium alloy was developed by the Zener-Hollomon parameter and the hyperbolic sine function. Meanwhile,the critical stress value of dynamic recrystallization was determined by the curve of strain hardening rate and stress. The results show that:in the process of hot compression defor-mation of the ZK60 and ZK60-1.0Er magnesium alloys,the flow stress decreases with the increase of deforma-tion temperature;the flow stress increases with the increase of strain rate. By adding rare earth Er,the flow stress and stress exponent increased,the critical stress value of dynamic recrystallization within 160~320℃increased as well. The existence of rare earth phase promoted the formation of the recrystallization grain nucle-ation due to the reduces of the average deformation activation energy Qˉ.%采用Gleeble-1500D热模拟试验机研究了稀土元素Er对ZK60镁合金的热压缩变形行为的影响。通过引入Zener-Hollomon参数和双曲正弦函数构建了ZK60和ZK60-1.0Er镁合金的本构方程，同时采用应变硬化率θ-流变应力σ关系曲线确定动态再结晶发生的临界应力σc值。结果表明：ZK60和ZK60-1.0Er两种镁合金在热压缩变形过程中，随着变形温度T的升高，压缩流变应力σ值均减小；随着应变速率ε̇的增加，流变应力σ值均增加。添加稀土元素Er使得ZK60镁合金热压缩变形流变应力σ值和应力指数n值增加，在变形温度为160~320℃时提高了发生动态再结晶的临界应力σc值，稀土相的存在促进了再结晶晶粒的形核，降低了平均变形激活能Qˉ值。
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