The effect of temperature on microstructural evolution under hot ECAP was studied in an as-cast 7475 aluminum alloy at temperatures from 523K to 673K. The samples were pressed by using route A up to strains of 12. The average (sub)grain size tends to increase with increasing temperature, e.g. about 0.6mum at 523K and 1.7mum 673K. The misorientation distribution of deformation induced dislocation boundaries shows a single peak type at low misorientation angles after first pass and gradually shifts to higher angles with increasing of strain. Equiaxial grains with high angle boundaries start to be formed after 3 passes and then gradually developed with repeated ECAP, finally leading to full development of a new grain structure with high grain boundaries of about 30degrees in high strain. Specific features of such microstructure evolution and continuous dynamic recrystallization mechanism are discussed in some details.