To provide a method capable of forming a harmonized and calm island like pattern having scaly brightness, excellent in the fitness to an undercoat layer and for forming a deep, calm and excellently durable decorative material on the whole and to provide a coating material suitable for forming the island pattern.

The undercoat layer 2 is formed by spraying a 1st coating material containing a synthetic resin emulsion 2b and aggregate 2a on a base material or a surface 1 to be coated. After or before drying, a 2nd coating material containing 100 pts.wt. aggregate 3a having 0.1-3 mm particle diameter, 15-60 pts.wt. synthetic resin emulsion expressed in terms of resin solid portion and 5-50 wt.% mica thin chips 3b, 60% of which is a non-artificially colored mica thin chips, per the weight of the aggregate 3a in a ratio to cover 20-80% of the area of the surface is applied to form nearly the island like pattern, pressed on the surface by a sponge roller and dried.