A beverage container is provided with a pull ring attached to the outer surface of the cap thereof and with a gas chamber disposed under the inner surface of the cap thereof. The gas chamber has a top lid provided with a whistling hole and a bottom lid provided with a small hole through which the gas produced by the beverage contained in the beverage container enters the gas chamber. As the pull ring of the beverage container is pulled out, the gas contained in the gas chamber is let out via the whistling hole, thereby producing a clear, loud and whistling sound.