An　approach　to　the　dynamic　modeling　of　flexural　beams　with　combined　loads　in　compliant　mechanisms　is　presented　in　this　study.　Based　on　the　pseudo-rigid-body　model　(PRBM),　a　PRR　pseudo-rigid-body　dynamic　model　(PRBDM)　is　proposed　to　deal　with　the　bending　and　stretching　deformations　of　flexible　beams　in　compliant　mechanisms.　The　motion　equation　of　the　PRR　PRBDM　is　obtained　from　Lagrangian　equation.　The　effectiveness　and　superiority　of　the　PRR　PRBDM　are　illustrated　in　the　numerical　investigations　on　the　dynamic　performance　of　flexural　beams　in　compliant　mechanisms.