Abstract. In this paper, we propose to endow a graphical representation of a user in Instant Messaging – an avatar – with the ability to recognize and to express emotions and to play social nonverbal behaviour, on the basis of textual affect sensing and interpretation of communicative functions conveyed by online conversations. The developed Affect Analysis Model integrated with Instant Messaging (IM) media supports the recognition of affect from text to ensure avatar animation in an appropriate and expressive manner