In order to realize a personification interface which is friendly and easy to use for a man , it is required to investigate how a man feels a personification agent. Especially in this research, paying attention to eye movements, eye gaze, eye blink and pupil diameter of a personification agent¡Çs synthetic facial expression were changed, and the subject experiment investigated the influence on the impression which the person who looked at it has. Consequently, also in a synthetic facial expression, it turns out that eye gaze and eye blink mainly participate in impression formation deeply.