Dry s tock of s ilica sol ceramic mold was prepared by the colloidal molding technique and optimized vacuum drying process. Effect of roas ting process on the shrinkage rate and compressive strength of silica sol ceramic mold was investigated. The materials used to prepare s ilica sol ceramic mold are JN-30 silica sol, silica powder and 15%NH4Cl solution. The optimum roasting temperature of silica sol ceramic mold gained by the experiments is 1 050 ℃ and holding time is 2 h. SEM shows that the refractory material particles in s ilica sol ceramic mold is a growing process during the roasting and cause small crack to occur.