A method of controlling a refrigerator includes: controlling a cooling unit such that an output of the cooling unit becomes a first reference output for a first reference time previously determined; controlling the cooling unit such that the output of the cooling unit becomes a second reference output for a second reference time previously determined; calculating a representative value of a temperature of a storage compartment for an operating period, which is made by a sum of the first reference time and the second reference time, and comparing the calculated representative value with a specific temperature in a temperature satisfying range of the storage compartment; and varying, by a control unit, at least one of the first reference time and the second reference time depending on a comparison result between the specific temperature and the representative value and controlling operating of the cooling unit based on a varied reference time.