This paper presents an approach to recognize human motion from singleviewed image sequencein order to realize a new man-computerinterface.Thehuman body is assumed to be linked model of rigid segments which are approximated by ellipsoids with three different length of diameter. The reconstruction of human motion is mainly performed by interpretationof 2D pattern deformation as 3D motion. We show the effectiveness of utilizing changes of curvature and discontinuityon the contourof 2D pattern for human motion reconstruction.