Experiments have been performed to investigate the effect of cooled-plate characteristic on frost formation under the condition of forced convection. Two kinds of plates having the different contact angles to water, were utilized. Special attention was focused on the incipient phenomena of the effect of the plate contact angle to water on the frost forming on the cooled plate. It was found that when the temperature difference between the cooled plate and the dew point of air stream, was less than about 1.50c the frost thickness might never build up greater than 0.5mm.