The emergence of “Sense of agency” contributes to self-recognition. However there are few useful experimental paradigms for evaluating the development process of the sense of agency in young infants because the sense of agency is a subjective sense and young infants cannot verbally describe their internal experience. In this article, we propose a new experimental paradigm for examining the sense of agency using on-line eye tracking which we named “eye-scratch task”. This task enables us to evaluate the emergence processes of the sense of agency by a trajectory of voluntary eye movement. Besides, this task enables direct comparison of eye movement trajectories between infants and adults in common criteria. Hence, we can discriminate whether an infant feels the sense of agency or not by comparison with adults. Further, we analyzed participants' behavior in the task by the concept of feed-forward model that are the most famous computational frameworks for motor control and sense of agency. And we claim that our new infant's model based measurement give fruitful suggestions to the computational modeling for the development process of the sense of agency and self-recognition.