Abstract: The relationship among the flow stress, the deformation temperatures and the strain rates of Mg₉₇Y₂Zn₁ magnesium alloy during hot compression deformation was investigated by using Gleeble3500 thermalmechanical simulator. And the corresponding flow stress model was established. The results indicate that the flow stress of the alloy decreases with increasing temperature at a given strain rate, and increases with increasing strain rate at a given temperature. The flow stress behavior of Mg97Y2Zn1 magnesium alloy during high temperature deformation can be represented by a ZenerHollomon parameter. The hot deformation activation energy of the alloy is 137.277 kJ/mol.