A low gloss ASA-based resin composition having excellent weatherability and heat resistance is provided. The low gloss ASA-based resin composition is obtained by blending a general SAN copolymer, a heat-resistant SAN copolymer, a crosslinked aromatic vinyl compound-cyanide vinyl compound copolymer, and an amorphous inorganic material with large diameter and extra-large diameter ASA graft copolymers at a predetermined composition ratio. The low gloss ASA-based resin composition is useful in the manufacture of a high-quality molded article in which gloss characteristics are uniformly exhibited because impact resistance, heat resistance, flowability, weatherability, and low gloss characteristics are all excellent, and particularly, the gloss deviation on the entire surface of the injection molded article is significantly reduced.