Ground　motions　recorded　in　near-fault　areas　have　some　specific　characteristics　that　differ　substantially　from　those　recorded　in　far-fault　regions.　One　of　the　main　features　of　near-fault　records　is　the　pulse-like　shape　caused　by　forward-directivity　effect.　This　peculiarity　may　lead　to　much　more　severe　damage　to　bridge　structures　located　in　near-fault　regions.　However,　both　current　Chinese　and　European　codes　for　seismic　design　of　highway　bridges　nearly　have　no　consideration　on　near-fault　seismic　actions.　In　this　study,　typical　regular　highway　bridges　in　China　are　idealized　as　single-degree-of-freedom　(SDOF)　systems.　Then,　the　Makris　mathematical　model　for　the　pulse-like　records　is　used　to　perform　a　parametric　analysis　on　a　settled　SDOF　system.　Effect　of　key　parameters,　such　as　the　half-pulse　number　(n),　fundamental　period　(T0),　pulse　period　(Tp)　and　the　peak　velocity　(Vp)　from　the　mathematical　model,　on　responses　of　SDOF　systems　are　analyzed.　The　potential　degradation　phenomenon　which　might　happen　under　near-fault　earthquake　ground　motions　is　also　considered　by　comparing　the　ductility　coefficient　spectrum.　The　results　show　that　all　the　key　parameters　had　a　significant　effect　on　both　linear　and　nonlinear　response　spectrum　and　seismic　response.　The　stiffness　degradation　phenomenon　will　lead　to　a　larger　ductility　coefficient　and　the　Vp　is　the　most　effective　factor　for　the　response　under　the　near-fault　mathematical　input.