A process for producing a polyphenylene sulfide resin composition includes melt-kneading about 99 to about 60 wt % of a polyphenylene sulfide resin (a) and about 1 to about 40 wt % of a polyamide resin (b), and about 0.1 to 10 parts by weight of a compatibilizing agent (c) per 100 parts by weight in total of the polyphenylene sulfide resin (a) and the polyamide resin (b), using a double screw extruder with two or more kneading portions at a temperature of the range from a melting peak temperature of the polyphenylene sulfide resin+10.degree. C. to a melting peak temperature of the polyphenylene sulfide resin+70.degree. C., wherein the polyamide resin (b) is excluded nylon 46 and has a relative viscosity of 1.5 or more measuring in concentrated sulfuric acid at a concentration of 1% and at 25.degree. C., wherein the compatibilizing agent (c) is a compound having one or more types of groups selected from epoxy groups, amino group and isocyanate group, and wherein the resin composition has a morphology that the polyphenylene sulfide resin (a) in the resin composition forms a sea phase while the polyamide resin (b) in the resin composition forms an island phase, and the number average dispersed particle size of the polyamide resin (b) is kept at less than about 500 nm after the resin composition is melted and allowed to reside at 300.degree. C. for 30 minutes.