Abstract: On the hasis of the reversible Carnot refrigerator model considering the losses of heat resistance between refrigerant and heat reservoirs,this article presents a new irreversible Carnot refrigerator model by taking account of the losses of heat leak and the other irreversibilities,such as friction,turblence,nonequiblium and so on,together with heat resistance by using a constant parameter and a constant coefficient.The relation between cooling load and COP（coefficient of performance） and the maximum COP and the corresponding ccoling Ioad are derived.