Abstract: Hot deformation behavior of the new hot-damage-resistant wheel steel 20CrSiMnMo was investigated by thermo-mechanical modeling tests in 850-1 250 ℃ and strain rate range 0.1-1 s-1.The results indicate that the flow curves at higher temperature and lower strain rate are characterized by dynamic recrystallization,and strain-hardening curves are obtained at lower temperature and higher strain rate.Kinetic analysis is carried out to determine the stress exponent n=5.56 and the activation energy Q=352.272 5 kJ/mol.Microstructure observation and processing map indicate that finer dynamic recrystallization grains and transformed structure will be obtained deforming in temperature and strain rate ranges of 1 000-1 100 ℃,0.1-05 s-1 or 1 250℃,1-0.25 s -1.