A method, which is for controlling a temperature of a refrigerating compartment, includes cooling the refrigerating compartment, cooling the freezing compartment, determining a temperature of the refrigerating compartment, and based on the temperature of the refrigerating compartment, controlling the refrigerating compartment to a constant temperature range by controlling opening and closing of first and second passages of a three-way valve of the refrigerator to alternate cooling the refrigerating compartment and cooling the freezing compartment.