Rotational molding has several advantages, such as suitable for small-lot manufacturing and will be needed for the 21st century. In this paper, after describing briefly the feature and the molding materials used for rotational molding, PP wax is taken up as one example of developing elastomeric materials. Research and development of the elastomeric materials were seldom done until now for the reason that the elastomeric material does not fit normal temperature pulverization. However, application is broad, such as products which combine rigidity and surface softness by multilayer molding, and the breakthrough in material’s R&D is expected.