A material for fuel-system parts which is excellent in impact strength, rigidity, elongation, unsusceptibility to swelling with liquid fuels including gasoline, and gasoline-barrier properties and has satisfactory moldability. The material for fuel-system parts comprises a resin composition comprising 100 parts by weight of a given polyamide resin (A) and 11 to 100 parts by weight of a resin (B) having a lower glass transition temperature than the polyamide resin (A) and having a functional group reactive with the polyamide resin (A), and has a structure in which the polyamide resin (A) serves as a matrix ingredient and the resin (B) serves as a domain ingredient.