To provide an unsaturated polyester resin composition, an unsaturated polyester resin material for molding, and a fiber-reinforced plastic molded article using the material which can realize a surface flatness sufficient for automotive exterior plates without adding a low-shrinkage agent as well as a method for preparing the article.

This unsaturated polyester resin composition comprises an unsaturated polyester resin, a polymerizing monomer and fine expandable particles as indispensable components. A fiber-reinforced plastic molded article is prepared by using an unsaturated polyester resin material for molding which comprises a reinforcing fiber as well as the unsaturated polyester resin composition.