In　order　to　undertake　the　hydraulic　analysis　of　urban　sanitary　sewer　networks,　the　stochastic　simulation　of　the　nodal　flow　series　is　conducted　in　the　paper.　Firstly,　the　measured　sewage　flow　series　are　scaled　by　the　average　flowrate,　and　then　the　dimensionless　ones　are　divided　into　several　states.　Secondly,　homogenous　Markov　chain　is　applied　to　modeling　the　nodal　flow　series,　and　the　universal　set　of　the　nodal　flow　simulated　series　is　gained.　The　correlation　coefficient　between　the　simulated　series　and　the　average　flow　series,　served　as　the　threshold　value,　is　used　to　justify　the　validity　of　the　simulated　series.　Then　the　suitable　flow　series,　namely　the　subset　of　the　total　set　above,　are　selected　as　the　final　nodal　flow　simulated　series.　Finally,　a　case　study　is　carried　out　employing　the　hourly　flow　records　of　a　wastewater　treatment　plant　in　Beijing.　Relying　on　the　Monte　Carlo　method,　homogenous　Markov　chain　is　simulated　on　computer　using　accumulative　state-transition　probability　matrix　while　the　flow-rate　within　every　state　interval　is　simulated　using　uniform　distribution.　This　method　is　proven　to　be　easier　to　use　than　the　non-stationary　time　series　analysis.