An ice supply system of a refrigerator is provided. The ice supply system of the refrigerator includes an icemaker, a container, a crusher and an ice discharger. The icemaker produces the ice by using cool air of the freezer and drops the ice to a lower part of thereof. The container is provided at a lower part of the icemaker. The container is insertable into and detachable from the door of the refrigerator. The container includes an open top, a first opening at a side thereof, a transfer device rotating and transferring the ice of the first opening, and an outlet for discharging the ice. The crusher crushes the ice transferred by the transfer device and the ice discharger is provided for discharging the ice to an ice chute at the door by controlling a size of an opening of the outlet.