Recently　the　parallel　manipulator　with　less　DOFs　has　attracted　industry　and　academia,　but　the　research　on　its　dynamics　is　still　an　open　problem.　In　this　paper,　the　inverse　dynamic　of　a　spatial　parallel　manipulator　with　two　translational　degrees　of　freedom　and　one　rotational　degree　of　freedom　is　studied　based　on　the　Newton-Euler　approach.　The　kinematics　analysis　is　firstly　performed　in　a　closed　form.　The　inverse　dynamic　equation　of　this　manipulator　is　formulated　by　using　the　Lagrange　multiplier　approach　and　choosing　the　Cartesian　position　and　orientation　as　the　generalized　coordinates.　Finally　a　numerical　example　is　given　for　the　kinematic　and　dynamic　simulation　of　this　manipulator.　The　model　will　be　useful　to　improve　the　design　of　the　mechanical　components　and　the　control　algorithm.　©　(2012)　Trans　Tech　Publications,　Switzerland.