With　the　continuous　expansion　of　the　railway　infrastructure　network,　the　railway　operation　network　has　become　more　and　more　complex　both　in　time　and　space　dimensions.　In　order　to　help　railway　operators　formulate　management　measures　more　pertinently,　this　research　aims　to　develop　a　method　to　analyze　the　complex　operation　network　via　quantifying　and　ranking　the　importance　of　stations　in　different　periods　based　on　the　train　timetable.　Firstly,　we　propose　the　time-space　train　origin-destination　(OD)　service　network　(OD-TS　network)　to　abstractly　describe　the　railway　transportation　service.　And　a　network　construction　method　is　designed　to　build　the　OD-TS　network　according　to　the　train　operation　information　in　the　timetable.　We　further　develop　an　improved　k-shell　decomposition　method　to　quantify　the　node　importance　for　the　directed-weighted　networks.　Case　studies　are　carried　out　based　on　the　train　timetable　of　China＇s　high-speed　railway.　We　study　the　OD-TS　network　from　three　perspectives　(the　global　network,　the　railway　hubs,　and　the　stations)　and　analyze　the　spatiotemporal　details　of　the　railway　operation.　These　analyses　show　that　the　proposed　method　can　help　the　railway　operators　mine　the　spatiotemporal　characteristics　of　the　railway　operation　well.