An energy-saving and high-efficiency shower head capable of producing a pulsating stream includes a main body having an inlet opening, an upper cover and a cover plate connected to the underside of the main body, a water-stop mechanism, and a face plate. The cover plate is formed with a water-passing chamber and a pulsating chamber having an oblique hole. The pulsating chamber is provided with at least two diversion holes to form two outlet passages. The water-stop mechanism is composed of an impeller and a water-stop piece disposed on the impeller. The water-stop piece alternately blocks one of diversion holes when the impeller rotates to intermittently open and close the outlet passages corresponding to the diversion holes, providing a pulsating stream effect.