Abstract: The effect of normalizing on phase transformation of ZG 230- 450 H during reheating process was investigated by using thermal/mechanical simulator and microstructure analysis.Results shown that due to refinement and homogenization of microstructures by normalizing, the starting and ending temperatures of austenite transformation were reduced. In the austenite cooling process, the starting temperature of ferrite transformation was reduced and the final finishing temperature of the phase transformation was increased.