The present invention provides a method of controlling a refrigerator, including a main body having a plurality of storage chambers; a plurality of evaporators installed to independently cool the plurality of storage chambers, respectively; and a refrigerant control valve for controlling refrigerant introduced into the plurality of evaporators, the method includes a refrigerant control valve opening step of opening the refrigerant control valve so that the refrigerant can be introduced into at least one of the plurality of evaporators; an evaporator defrost step of, when an opening integration time of the refrigerant control valve is higher than a defrost setting time of the evaporator, at which the refrigerant is introduced by the refrigerant control valve, operating the refrigerator in a defrost mode of the evaporator in which the refrigerant is introduced; and an evaporator defrost end step of, when temperatures sensed by defrost sensors of the evaporators that are being defrosted are higher than return setting temperatures after the evaporator defrost step begins, ending the defrost mode of the refrigerator. Accordingly, the present invention is advantageous in that it can defrost each evaporator efficiently at an exact point of time at which defrosting is required.