To provide a rotor for electric water pumps in which a sliding bearing formed of a thermoplastic resin composition can be produced at a low cost and has superior low friction and low wear property, and an inner diameter of the sliding bearing is hardly contracted by the insert-molding. A rotor 1 used for electric water pumps has a main body 2 that supports an impeller of the pump, a sliding bearing 3 that rotatably supports a shaft, and a magnet 4 disposed to face a stator. The sliding bearing 3 is an annealing treated body of a polyphenylene sulfide resin composition. The polyphenylene sulfide resin composition contains 5-30 vol% of carbon fiber, 1-20 vol% of polytetrafluoroethylene resin and 1-30 vol% of graphite relative to the whole volume of the polyphenylene sulfide resin composition. The main body 2 is an injection-molded body disposed by insert-molding a thermoplastic resin composition, which is different from the polyphenylene sulfide resin composition, at an outer diameter side of the sliding bearing 3.