To provide an unsaturated polyester resin composition whereby a molded product with an excellent heat-resistance of thermal deformation temperature ≥150°C can be obtained, even if the curing is performed at a relatively low temperature and a used mold is one used conventionally, and to provide a molded product which is excellent in heat-resistance and inexpensive.

The resin composition is obtained by dissolving an unsaturated polyester resin (a) of 50-70 pts.wt., which is obtained by reacting an acid component being α,β-unsaturated polybasic acid of 60-90 mol% and 2,6-naphthalene dicarboxylic acid compound or its derivative of 10-40 mol% with a polyhydric alcohol, in a polymerizable monomer (b) having one or more polymerizable double bond in a molecule of 30-50 pts.wt. (a total amount of (a) component and (b) component is adjusted to achieve 100 pts.wt.). A glass fiber reinforced plastic molded product comprises the resin composition and a glass substrate.