Abstract: A defrost control apparatus for refrigerator includes a microcomputer which counts the number of opening/closing times of a door of a storage room for each of time zones within a day so as to set indexes for every time zones on the basis of the number of opening/closing times. The microcomputer also counts operating hours of a compressor and total elapsed hours, and determines a sudden phenomenon and a season. The microcomputer further selectively fetches the indexes, and generates a single index by joining a plurality of indexes so as to apply the same to a neural network included in a defrost signal generating unit. The neural network generates a defrost on/off signal on the basis of inputted data. In addition, if feature amounts are generated on the basis of the indexes by a feature detecting unit, the neural network generates the defrost on/off signal on the basis of the feature amounts.