To provide a resin composition composed mainly of a polyamide and an ABS resin, which excels in low water absorption, dimensional stability, mechanical properties at water absorption, heat resistance, moldability and chemical resistance and also has a low specific gravity, and to provide a resin molded product consisting thereof.

The resin composition is obtained by melt-kneading 5-20 parts by mass of an acid-modified styrene-based elastomer, 0.05-5 parts by mass of an unsaturated carboxylic acid, unsaturated dicarboxylic acid or acid anhydride thereof and 0.01-3 parts by mass of a radical generator, based on 100 parts by mass of a polyamide/ABS resin composition which consists of 40-80% by mass of a polyamide containing 0.01-20% by mass of a swelling fluorine mica type mineral, obtained by polymerizing the monomer under co-existence of the swelling fluorine mica type mineral, and 60-20% by mass of an ABS resin.