Motion style is essential in defining the characteristics of motion, as it shows the context of motion,e.g., the mood, behavior. In particular, the motion style of 3D human avatars is a crucial visual trigger for accurate and effective interaction with users in Virtual games, shopping, education, and psychotherapy. However, the perceiving and interpreting motion styles are somewhat subjective, and thus may vary significantly from person to person. In this thesis, we standardize the motion style framework and focus on the different perceptual features of motion style. We defined the motion style to reflect the character’s intrinsic characteristics, e.g., personality, emotions, and extrinsic characteristics, e.g., motivation, objective. Then we propose frameworks that can define these two attributes. In the first part, we suggest two frameworks: six categories of Stanislavski’s Method acting system and the Effort theory of Laban Movement Analysis (LMA). In the second part, we examine the perceptual features of the two motion style frameworks. In the third part, we generate an empathic virtual avatar and examine the perceptual characteristics of the motion style frameworks defined above through actual examples. In the end, we propose the direction of future motion style research.