Abstract: Using a thermomechanical simulator, single-pass compression tests were carried out to clarify the dynamic recovery behavior in the hot deformation process of ultra-purified Cr17 ferritic stainless steel. The microstructure evolution during hot deformation was investigated at 900~1150°C with the maximum true strain of 0.8 and strain rate of 1 s^-1. The results show that the stress-strain curves of single-pass compression are all characterized by dynamic recovery. As deformation temperature increases, the dynamic recovery occurs much faster. When the compression is performed at low temperature, deformed grains are formed and bulging of initial grain boundary occurs. While, at high temperature, the microstructure evolution will be characterized with the formation of a large quantity of sub-grain boundaries and sub-grains.