Abstract: The hot compression deformation behavior of Nb microalloyed 9310 steel was investigated using Gleeble-3800 simulator in the temperature range of 1 173-1 473 K with the strain rate of 0.01-10 s-1 to get the flow curves of test steel. And the microstructure of hot deformed test steel was observed using optical microscopy. The results show that the flow stress and peak strain of Nb microalloyed 9310 steel increased with the increase of strain rate and the decrease of deformation temperature. When the true strain was 0.9 and the range of strain rate was at 0.01-10 s-1, the temperature for full dynamic recrystallization increased with raising the strain rate. The hot deformation activation energy Q of Nb microalloyed 9310 steel was 362.649 kJ·mol-1. The hot deformation equation and the relationship between the peak strain σp and Zener-Hollomon parameter were obtained.