Experimental studies for crystal ice formation and its removal phenomena of ethylene glycol solution on a cooled horizontal plate have been performed. Onset condition for ice removal phenomenon is examined experimentally as well as analytically. As a cooled plate, a glass, an acrylic resin, a polyvinyl chloride, a silicone resin and the copper plates are used. It is found that the removal or unremoval of crystal ice is related to the heat flux at the cooled plate surface when the latent heat of freezing is discharged with ice formation, and that the heat flux ratio, q(2)/q(1), is an important parameter of the onset condition for ice removal, where q(1) represents the heat flux from the plate surface to the cooled plate and q(1) represents the heat flux from the plate surface to the solution. II is also found that the occurrence of ice removal phenomenon is easier in the case of plastic cooling plates than that of metal ones.