Abstract: According to thermodynamic theory,thermodynamic numerical analysis about the transformation of deformed austenite to ferrite of steels with different compositions was carried out by using the software Thermo-Calc.The compression tests were performed on thermal simulator Gleeble 2000 and the experimental results were compared with calculated results.The results show that the deformation could enhance the equilibrium transformation temperature of austenite to ferrite,increase the transformation driving force,which accelerated the transformation.The deformation could also increase the carbon content in austenite phase.The simulated results were in agreement with experimental ones.