A method for controlling the amount of a refrigerant of a dual type unitary air conditioner, which has a plurality of centralized warm and cold air circulators and at least one individual warm and cold air circulator, includes inputting the operation capacity of compressors of an outdoor unit of the dual type unitary air conditioner; setting a superheating temperature of the individual warm and cold air circulator to a relatively low value when the operation capacity is large, and setting the superheating temperature of the individual warm and cold air circulator to a relatively high value when the operation capacity is small; and controlling the amount of the refrigerant supplied to the individual warm and cold air circulator according to the superheating temperature, thereby appropriately maintaining the amount of the refrigerant supplied to the individual warm and cold air circulator provided in a designated place and thus forming the optimized refrigerant cycle.