Segmented　tunnels　are　widely　used　nowadays.　However,　most　existing　studies　on　the　seismic　response　of　underground　tunnels　are　based　on　the　model　of　continuous　linings,　without　considering　the　segment　joints.　This　paper　presents　a　numerical　study　aiming　to　investigate　the　factors　that　affect　the　seismic　response　of　segmented　tunnels,　with　a　step　further　than　previously,　considering　obliquely　incident　seismic　waves.　The　numerical　simulation　is　carried　out　by　a　2.5D　coupled　finite　element-boundary　element　(FE-BE)　model,　which　can　properly　simulate　the　soil-tunnel　interaction　for　obliquely　incident　seismic　waves　and　predicts　both　the　transverse　and　longitudinal　seismic　responses　of　the　tunnel.　It　is　shown　that　the　joint　distribution　is　one　of　the　critical　factors　that　determine　the　seismic　responses　of　the　segmented　tunnel,　and　the　influence　of　the　segment　joints　tends　to　be　more　pronounced　when　they　are　located　near　the　positions　of　large　transverse　bending　moments　in　the　tunnel　lining.　Compared　with　the　homogeneous　tunnel,　the　reduction　in　the　transverse　bending　moment　and　axial　force　of　the　segmented　tunnel　is　significant,　while　it　is　minor　in　the　longitudinal　bending　moment　and　axial　force,　and　the　effect　of　the　segment　joints　highly　depends　on　the　soil-tunnel　relative　stiffness.　In　addition,　the　influence　of　the　spectral　characteristics　of　the　input　motions　on　the　tunnel　responses　is　highlighted.