This　study　develops　a　simulation　method　of　water　supply　network　against　earthquakes　based　on　pressure　drive　demand　model.　For　this　purpose,　Monte　Carlo　method　is　used　for　the　probabilistic　seismic　simulations　and　the　mean　system　serviceability　is　obtained　as　the　final　analysis　result.　In　each　simulation,　a　post-earthquake　water　supply　network　hydraulic　model　comes　into　being　as　a　result　of　random　selection　of　pipelines　status,　then　the　system　serviceability　is　calculated　through　hydraulic　analysis　based　on　pressure　drive　demand　model.　In　case　analysis,　we　use　the　developed　method　and　GIARFFE　software　developed　by　professor　O＇Rourke　from　Cornell　University　to　analyze　an　urban　water　supply　network　performance　under　different　earthquake　intensities.　The　results　show　that:　the　results　between　the　developed　method　and　GIRAFFE　have　the　same　trends,　the　developed　method　needs　less　number　of　Monte　Carlo　simulation　than　GIRAFFE,　and　less　operation　time　than　the　GIRAFFE　in　a　single　simulation;　a　damaged　pipeline　reduces　both　of　upstream　and　downstream　nodes　serviceability　in　the　analysis　based　on　pressure　drive　demand　model.　©　2019,　Science　Press.　All　right　reserved.