A　simplified　grillage　bridge　model　suitable　for　parametric　study　of　skew　bridge　is　presented,　and　the　formulae　for　computing　the　seismic　response　of　skew　bridges　are　developed.　Considering　the　existence　of　crossbeams　and　elastic　bearings,　the　effects　of　stiffness　eccentricity　ratios,　frequency　ratios,　the　number　of　beams　and　skew　angles　are　assessed　using　response　spectrum　analysis.　The　results　show　that　the　natural　frequencies　and　mode　shapes　depend　mainly　on　the　stiffness　eccentricity　ratio　and　frequency　ratios.　The　study　also　demonstrates　that　the　seismic　response　of　skew　bridge　is　influenced　quite　noticeably　by　stiffness　eccentricity　ratio　and　frequency　ratio.　The　maximum　seismic　response　of　skew　bridge　can　be　reduced　by　increasing　stiffness　eccentricity　ratio　and　frequency　ratio.　Based　on　this　study,　a　theory　to　evaluate　the　dynamic　behavior　and　seismic　response　of　skew　bridges　is　presented　and　it　can　be　conveniently　applied　in　bridge　seismic　design.　©　(2011)　Trans　Tech　Publications,　Switzerland.