To provide a dental model fabrication method which can shorten the time of curing an impression material, a disinfection/sterilization step, and a long gypsum curing time for abridging working steps of fabricating a dental model and is simple and low-cost.

For the purpose of achieving a low-cost dental model fabrication method, the method is characterized in that a material used in the dental model fabrication is mixed with alum water. Alum water cannot only accelerate the time of curing an impression material or gypsum but also can markedly abridge working steps in virtue of its sterilization action and astringent action. The subject of an impression material mixed with the alum water is an impression material composition based on mainly a soluble alginate and is generally effective dental gypsum. The alum water is a desirably an aqueous solution of 0.01-5 wt.% alum concentration. The concentration of the alum water is adjusted according to the type, i.e., characteristics, of an impression material or gypsum.