To improve the appearance of protection concrete such as an inclined side face of a highway, by sticking granular materials on a molding body with a rugged face through an adhesive and charging a water-absorbing polymer among the granular materials and placing concrete.

An adhesive 3 is applied to a molding body 2 provided with ruggedness on the whole face to stick granular materials 4 of several mm- several cm and further stick water-absorbing polymer powder among the granular materials 4. Then the molding body 2 is assembled and a cement hardener 6 is placed. The polymer 5 absorbs water and swells like a jelly to prevent the cement hardener 6 from penetrating into the granular materials 4. Hence, after curing, when the molding body 2, the adhesive 3, and the water-absorbing polymer 5 are removed, the upper parts of the granular materials 4 are exposed on the surface. Accordingly, joints, figures, patterns, etc., are formed and the appearance thereof is improved, depending on the arranged and colored granular materials. The granular materials 4 are stuck on a sheet having adhesive layers at both faces and then, the rear face may be stuck to the molding body 2.