A　dynamic　wear　prediction　methodology　is　proposed　to　investigate　the　coupling　effects　between　surface　wear　and　dynamics　of　spur　gear　systems.　The　overall　computational　scheme　combines　a　quasi-static　wear　model　and　a　translational-rotational-coupled　nonlinear　dynamic　model.　The　worn　surfaces　are　represented　by　modulated　mesh　excitations　and　introduced　into　the　dynamic　model　to　investigate　the　effects　of　surface　wear　on　system＇s　dynamic　characteristics.　The　dynamic　gear　mesh　forces　are　converted　into　an　equivalent　load　by　using　the　Miner　rule　to　reveal　the　effects　of　dynamics　on　wear　behaviors.　A　spur　gear　transmission　is　taken　as　an　example　system　to　demonstrate　the　interactions　between　surface　wear　and　dynamic　behaviors.　The　simulations　indicate　that　surface　wear　and　gear　dynamics　are　highly　interacted.　©　2016　Elsevier　Ltd.　All　rights　reserved.