In　order　to　recover　the　motion　ability　of　the　patient＇s　ankle　joint,　a　practical　3DoF　(degree　of　freedom)　2-UPS/RRR　parallel　mechanism　with　simple　structure　is　presented,　based　on　the　analysis　on　the　mechanisms　of　existing　robots　for　ankle　rehabilitation.　The　mechanism　center　of　rotation　matches　accurately　with　the　center　of　rotation　of　each　patient＇s　ankle,　owing　to　the　design　of　constraint　branches　and　the　moving　platform　in　this　paper.　Inverse　kinematics　of　the　mechanism　is　solved　using　the　analytical　method　by　calculating　the　freedom　of　the　mechanism,　and　thereby　the　velocity　Jacobian　matrix　is　established.　Then,　the　workspace　of　the　mechanism,　which　should　meet　all　the　training　requirements,　is　solved　by　demarcating　the　driving　parameters.　Lastly,　the　kinematics　performance　of　the　mechanism　is　analyzed　in　simulation　based　on　the　Jacobian　matrix.　The　results　show　that　the　mechanism　is　of　favourable　operability,　flexibility　and　stiffness　characteristics　within　the　specified　workspace.　Moreover,　the　non-redundant　electric　motor　is　in　simple　structure,　unnecessary　interferences　between　the　branches　are　effectively　avoided,　and　the　occupancy　volume　of　the　entire　unit　is　distinctly　reduced,　which　are　superior　to　some　existing　ankle　rehabilitation　robots.　©　2016,　Science　Press.　All　right　reserved.