A system and method for allowing a 2D character to perform a 3D motion having x-axis, y-axis and z-axis information is provided. In the present invention, 3D human motion data entered is analyzed to obtain motion information of angles, coordinates and depths of all human body parts in the 3D motion data. By matching a sprite with the 3D motion, an image of each body part of the 2D character is capable switching to a reasonable image for a particular angle according to angle information of the 3D motion data, and adjusting a size or deforming the image of each body part of the 2D character according to the depth and angle information of the 3D motion data. Therefore, the 2D character is allowed to achieve visual performance effects of frontal performance, sideways performance, turning performance or rear performance having depth information as a 3D character.