The heat partitioning to workpiece is an important parameter, which affects the grind-hardening technology. In this paper, the heat sources positions, which are around the grain, are analyzed. Ignoring the heat source produced in chip-grain interface, the heat partition model is established based on heat source position produced in grain-workpiece interface and the chip-workpiece interface. The heat partition is validated by using of finite element method and the experimental method. The results indicate the heat partition model can be used in grind-hardening temperature calculation.