A refrigerating system may include a compressor configured to compress a non-azeotropic mixed refrigerant, a condenser configured to condense the compressed non-azeotropic mixed refrigerant, a three-way valve configured to branch the non-azeotropic mixed refrigerant condensed by the condenser, a first evaporator configured to supply cold air to a first interior space, a second evaporator configured to supply cold air to a second interior space at a temperature higher than at a temperature of the first interior space, and a capillary tube configured to expand the non-azeotropic mixed refrigerant branched by the three-way valve and supply the expanded non-azeotropic mixed refrigerant to at least one of the first evaporator or the second evaporator. With such features, a high-efficiency refrigerating system to which the non-azeotropic mixed refrigerant is applied may be implemented.