The phase transformation temperature of ordered β to disordered β in the Cu-Zn alloy was tested by DSC. The transformation activation energy was calculated and the effect of deformation of the phase transformation was discussed. The results show that the phase transformation temperature and activation energy of ordered β to disordered β in the Cu-Zn alloy can be decreased going through deformation, and the phase transformation time can be also decreased. As a result, the order-disorder phase transformation occurs more easily.