Recently, with the development of good elastic impression materials and impression technique, very precise impression became available. Also, it is well known that forming precise impression of complete denture is important factor in the process of making denture which fits to a living body.Various technique of forming impression to make denture are reported. As to forming impression at edentulous jaw, there are the ways such a pressurized impression, non-pressurized impressionand selective pressure impression in accordance with the degree of pressurization on oral mucosa. Among there ways of impression, the factors of controlling impression pressure are fluidity of impression material, forms of individual tray (vent, spacer and relief, etc.) and how to giving pressure (pressure load, pressure speed) are considered.Accordingly, could not recognize the big difference in impression pressure among the impression materials made by different manufacturer. On the other hand, it has been clarified that the fluidity of the impression material and quantity of impression material have largely affected on the impression pressure.The thickness of the spacer has also affected the mutation of impression, and appropriate thickness to minimize the impression pressure has been a sheet of paraffin wax.As a result, herewith report that have contrived “the condition in the ways of gaining the impression” which proves the obtain ability of more precise impression.