The effects of temperature and strain rate on the semisolid deformation behavior of a high Zr WE54 magnesium alloys were studied at temperatures of 570, 595 and 620 °C. A flow stress peak was appeared during deformation of the feedstock experimental material at deformation conditions of 570 °C, 0.010 and 0.100 s−1, and 595 °C, 0.100 s−1. The latter results were connected to the occurrence of dynamic recrystallization in solid globules. Also, these conditions were gauged to be able to activate “lubricated flow” mechanism. At 570 °C and strain rate of 0.001 s−1 as well as 595 °C and rates of 0.010 and 0.001 s−1, the flow stress increases and reaches a plateau, where dynamic recovery is considered as the dominant mechanism. However, at 620 °C under all the strain rates, the flow stress drops for a limited strain range and then increases again. The results show that as the liquid removes from the boundaries between the solid parts, the densification of the globules occurs at higher strains, causing an increase in the flow stress. Comparative analysis points out that the feedstock material exhibits a lower flow stress than as-cast alloy associating with a modified morphology of Zr particles after deformation.