A water-oil emulsion which is a mixture of silanol-aqueous solution and silicone oil was cooled under stirring in a vessel in order to form ice particles without adhesion. A volume ratio of water in the emulsion was changed from 80vol.% to 100vol.% and the effects of the ratio on ice formation process were investigated. It was confirmed that oil in the emulsion restrained ice from adhesion to a cooling wall Water-oil emulsion with 80vol.% water is most effective in preventing ice adhesion under various cooling conditions examined. If a cooling temperature is higher and there is no ice adhesion, silanol-aqueous solution without oil can form ice with a higher heat transfer rate.