1. An avatar facial expression representation apparatus, comprising: a vocal information processing unit to output vocal information including at least one of an emotional change of a user and a point of emphasis of the user from vocal information generated by a user's voice; a pronunciation information processing unit to output pronunciation information including a change in mouth shape of the user from pronunciation information generated by the user's voice; an image information processing unit to output facial information by tracking facial movements and changes in facial expression of the user from image information; and a facial expression processing unit to represent a facial expression of an avatar using at least one of the vocal information output from the vocal information processing unit, the pronunciation information output from the pronunciation information processing unit, and the facial information output from the image information processing unit.