To decorate the front of a slope reliably by integrating crosspieces with rear sides of multiple corrugated portions divided longitudinally, providing mounting holes into which bolts are inserted, penetrating the crosspieces, and forming a decorative board made of a synthetic resin.

Crosspieces 12 are integrated with the rear sides of multiple corrugated portions 11 divided longitudinally, providing mounting holes 13 into which bolts are inserted, penetrating the crosspieces 12, and a slope reinforcing decorative board 10 is formed integrally of a synthetic resin material. To construct it, an embankment and ground reinforcing materials are laid on the graded ground, and blocks are wrapped by folding one end on the slope side of the reinforcing material and the other end on the other side of the reinforcing material is fixed to the ground or natural ground with piles. A decorative board 10 is butted against the fronts of the blocks through the reinforcing material and bolts are inserted into the mounting holes and fixed to the blocks. In addition, by repeating the same process, a slope of a prescribed height is formed, thereby making it possible to decorate and protect the front of the slope reliably.