We proposed the new model, "series-parallel combined model", for the fatigue of Ti-Ni-Cu SMA subjected to cyclic superelastic deformation. The model was selected considering the peculiar fatigue due to the cyclic phase transformation of Luders deformation style. The model was used to predict the fatigue crack origin in the fracture surface and qualitatively the effect of cold working on fatigue life. The predictions showed that fatigue life was governed by the failure of the earliest transformed martensite phase, and fatigue life decreases with increasing the cold working ratio. The prediction by our new model was clarified to agree well with experimental result and fracture surface observation by an electron microscope.