Computational models are becoming important tools in psychology. They offer a way to describe and investigate behaviors and physiology of living systems. However, it has yet been sufficiently discussed how they contribute to studies on emotion. In this paper, I discuss the role of the computational models in studies on emotion, introducing example studies. Emotions emerge as a construct that corresponds to variables or parameters of computational models during the processes of modeling behavioral or physiological data. Computational models also contribute to clarify the function of emotions in adaptive behaviors.