Exothermal behavior is always present during the hydration of cements. The biocompatibility and curing effect of a bone cement is in close relationship with its exothermal behavior. The exothermal behavior in the hydration process of the partially crystallized calcium phosphate (PCCP)+dicalcium phosphate anhydrate (DCPA) system cement was studied in this article. The results show that with the decrease of the particle size of DCPA, the heat release rate was greatly increased; whereas, with the decrease of the particle size of PCCP, the heat release rate was not obviously altered. The heat release in the hydration process of the PCCP+DCPA system cement was only 137 J/g, which was quite smaller than that of the tetracalcium phosphate (TTCP)+dicalcium phosphate dihydrate (DPCD) system cement, and the temperature increase was very small for this cement.