Abstract: Ceramic mold used in HIP process was required to has not only proper strength at room temprature but also better plasticity at elevated temperature so the ceramic mold must be sintered in a special way.Physical and chemical changes of sintering the ceramic mold were investigated,and a novel sintering process was designed.Experimental results showed that the transformations of crystal type in SiO₂ particles lead to violent changs of the particle volume,which can result incracking or distorting of the ceramic mold.However,the volume change of SiO₂ particles was properly controlled with the designed sintering process and any cracking or distorting of the ceramic mold was avoided.It was found that addition of MgO and TiO₂ particle decreased the sintering temperature remarkablly and the ceramic mold could be sintered just at 1100℃.