Abstract: Continuous cooling transformation(CCT) tests at different deformation condition are carried out on the MMS-200 thermal simulator.Phase transition temperature of the tested steels at different cooling rates are determined through thermal expansion method combined with metallographic method.The percentage content of pearlite is defined and microstructure of test steel is observed in utilization of optical microscope and scanning electron microscopy(SEM).Continuous cooling transformation(CCT) curve of the tested steel under deforming and non-deforming condition is drawn afterwards,and finally the effect of different deformation process on continuous cooling transformation behavior and microstructure of microalloyed steel is concluded.