A motion evaluation system includes a marker member including a body part having a first surface and a second surface parallel to the first surface, a reference indication part indicating a center of the first surface, and a plurality of markers arranged on the first surface to be spaced apart from the reference indication part. The marker member is arranged on an object such that the reference indication part is arranged at a reference point of a first coordinate system. A plurality of cameras generate coordinate images by respectively photographing the markers. A first coordinate calculator calculates first coordinate values of the markers in a first coordinate system by using separation distances of the markers and a first distance between the first surface and the second surface, the separation distances and the first distance being previously stored. A second coordinate calculator calculates second coordinate values of the markers in a second coordinate system by using the coordinate images generated by the cameras. A coordinate converter produces a conversion relationship between the first coordinate system and the second coordinate system by using the first coordinate values and the second coordinate values of the markers, and converts second motion information in the second coordinate system corresponding to a motion of the object objected by using the cameras to first motion information in the first coordinate system.
