Motion retargeting can be achieved by direct shape deformation transfer but may be visually unrealistic and physically incorrect. The purpose of this study is to include the consideration of physical properties for more realistic target motion synthesis. After partitioning source and target objects into segments, each segment mass and center of mass (COM) position/velocity are estimated. The target animation is generated by minimizing the difference in total linear momentum between source and target. Weighting functions for addressing the importance of segment motion and constraints on unrealistic segment length/velocity are also included. The results show that target movement amplitude and velocity are generally smaller than those of the source animation and with less seemly unrealistic motion. Thus, plausible animation can be generated by the retargeting procedures proposed in this study. The same methods may be applied to a variety of different target models for realistic motion synthesis.