This paper deals with the haptic affective social interaction during a greeting handshaking between a human and a humanoid robot. The goal of this work is to study how the haptic interaction conveys emotions, and more precisely, how it in'uences the perception of the dimensions of emotions expressed through the facial expressions of the robot. Moreover, we examine the bene'ts of the multimodality (i.e., visuo-haptic) over the monomodality (i.e., visual-only and haptic-only). The experimental results with Meka robot show that the multimodal condition presenting high values for grasping force and joint stiffness are evaluated with higher values for the arousal and dominance dimensions than during the visual condition. Furthermore, the results corresponding to the monomodal haptic condition showed that participants discriminate well the dominance and the arousal dimensions of the haptic behaviours presenting low and high values for grasping force and joint stiffness.