Abstract: Disclosed herein is an electronic water pump for vehicles. The electronic water pump includes an inner motor casing (150), a rotor (160) and a cooling unit (170). A shaft (152) is installed in an insert hole (151) of the inner motor casing, and a stator (140) is fitted over the inner motor casing. The inner motor casing has a depression (153) and at least one through hole (156). The rotor is disposed in the insert hole (151) so as to be rotatable around the shaft (152). A permanent magnet (162) is provided in the rotor. The cooling unit includes an upper cooling plate which is fitted over the rotor and is seated into the depression, at least one cooling pin which is coupled to the upper cooling plate and inserted into the through hole, and a lower cooling plate which is coupled to a lower end of the cooling pin.