A polyphenylene sulfide resin composition including (a) 25% to 75% by weight of a base resin; (b) 0.1% to 10% by weight of a laser direct structuring (LDS) additive; (c) 0.1% to 5% by weight of a plating seed generation promoter; (d) 10% to 60% by weight of a glass fiber; and (e) 0% to 40% by weight of a mineral filler, based on a total weight of the polyphenylene sulfide resin composition. The base resin includes 95% by weight or more of a polyphenylene sulfide resin based on a total weight of the base resin. A method of preparing the polyphenylene sulfide resin composition, and an injection-molded article manufactured using the polyphenylene sulfide resin composition.