The　dynamics　of　3-DOF　spatial　parallel　manipulators　with　flexible　links　were　performed.　Firstly,　a　model　of　spatial　flexible　beam　element　was　proposed,　and　the　dynamic　equations　of　elements　and　branches　of　the　parallel　manipulator　were　derived.　Secondly,　using　the　kinematic　and　dynamic　constraint　equations　of　the　parallel　manipulator,　the　overall　system　dynamic　equations　of　the　parallel　manipulator　were　obtained　by　assembling　the　dynamic　equations　of　branches.　Thirdly,　the　dynamic　responses　of　the　3-RRS　parallel　mechanism　with　flexible　links　were　analyzed　through　numerical　simulation.　This　paper　can　provide　necessary　information　for　the　dynamic　performance　analysis,　dynamics　optimization　design　and　control　of　the　3-RRS　flexible　parallel　mechanisms.　©2010　IEEE.