To provide a resin composition which can be used widely as various materials for a car, a home electrical appliance, a food container, a package, an information instrument, a building, and has rigidity, heat resistance and impact resistance in combination, and a resin composition which can develop excellent physical properties without using an expensive and hard-to-sort filler having high specific gravity and has excellent recyclability.

Disclosed is a crystalline thermoplastic resin composition wherein a polyethylene resin composition, which is obtained by melting/kneading an at least partially cross-linked polyethylene resin (hereafter called 'a cross-linked polyethylene resin') together with a compatible component (hereafter called 'a compatibilizing material') with the cross-linked polyethylene resin and a crystalline thermoplastic resin, is dispersed in the crystalline thermoplastic resin.