A polyphenylene sulfide resin composition includes a polyphenylene sulfide resin (A), an amino group-containing compound (B), an epoxy group-containing elastomer (C), wherein the polyphenylene sulfide resin (A) forms a continuous phase and the amino group-containing compound (B) and the epoxy group-containing elastomer (C) form a dispersed phase in the morphology of a forming product composed of the resin composition observed with a transmission electron microscope, and the modulus of elongation (the elastic modulus determined by performing a tensile test on an ASTM type 1 dumbbell test piece obtained by injection molding at a cylinder temperature of 300° C. and at a mold temperature of 150° C., under the conditions in which the distance between chucks is 114 mm, the test piece distance is 100 mm, and the elongation rate is 10 mm/min) of the resin composition is 1.0 MPa or more and 1000 MPa or less.