Magnesium alloys are important materials in industries because of their low densities. But the problem with these alloys is their lack of creep resistance at high temperatures. In this research, the creep behavior of cast ZE63 and ZE41 magnesium alloys were studied by using the impression creep method. The tests of impression creep were carried out at a temperature of 473 Kelvin and constant punching stress range of 175MPa to 500MPa. Microstructural investigation of magnesium alloys was performed using an optical microscope and X-ray diffraction (XRD). The results of XRD analysis indicated that the structures of both alloys were composed of α-Mg matrix phase accompanied by Mg7Zn3, Mg12RE, and Mg17RE2 intermetallic compounds. Besides, the analysis of the microstructure of deformation zones showed that the creep resistance of ZE63 was higher than ZE41. The higher creep resistance of ZE63 was attributed to the existence of more continuous phases of Mg7Zn3, Mg12RE, and Mg17RE2. Manuscript profile