Abstract: The hot deformation behavior of the austenite-ferrite duplex stainless steels 00Cr22Ni5Mo3N and 00Cr22Ni1Mo0.7N were investigated experimentally in the temperature range from 1000 to 1200°C and at the strain rates from 0.01 to 30 s^-1 by hot compression tests. With the experimental data, two relevant equations of hot deformation were given, where the activation energy was 534 kJ/mol and 482 kJ/mol, respectively. It was found that the optimum regions for hot working are of comparatively high temperature and low strain rate, where the fully dynamic recrystallization/recovery of austenite and ferrite come to pass during hot deformation, while in the regions of comparatively low temperature and high strain rate, the microstructure exhibits intense flow localization, even cracks observable during deformation.