An alarm system for refrigerator includes a sensor, a display, an alarm device, and a controller. The sensor is provided in the refrigerator for sensing temperature of a cooling chamber. The display is provided in the refrigerator for displaying operational information of the refrigerator, and the operational information includes the temperature detected by the sensor. The alarm device is for determining alarming situations using the temperature of the refrigerator detected by the sensor and issuing an alarm such that a user is notified of problems determined by the alarm device. The controller is provided in the refrigerator for controlling operation of the refrigerator, the sensor, the display, and the alarm device. The alarm device is controlled and operated by the controller in determining the alarming situations and issuing the alarm.