The　analysis　of　transport　networks　is　an　important　component　of　urban　and　regional　development　and　planning.　Based　on　the　four　main　stages　of　China＇s　railway　development　from　2008　to　2017,　this　paper　analyzes　the　hierarchical　and　spatial　heterogeneity　distribution　of　train　flows.　We　found　a　high　degree　of　spatial　matching　with　the　distribution　of　China＇s　main　railway　corridors.　Then,　using　a　classical　community　detection　algorithm,　this　paper　attempts　to　describe　the　functional　structure　and　regional　effects　of　China＇s　railway　network.　We　also　explore　the　impacts　of　construction　policies　and　changes　to　train　operations　on　the　spatial　organizing　pattern　and　evolution　of　network　hierarchies.　The　results　of　this　empirical　study　reveal　a　clear　pattern　of　independent　communities,　which　in　turn　indicates　the　existence　of　a　hierarchical　structure　in　China＇s　railway　network.　The　decreases　in　both　the　number　of　communities　and　average　distance　between　community　centers　indicate　that　the　newer　high-speed　rail　services　have　shortened　the　connections　between　cities.　In　addition,　the　detected　communities　are　inconsistent　with　China＇s　actual　administrative　divisions　in　terms　of　quantity　and　boundaries.　The　spatial　spillover　and　segmentation　effects　cause　the　railway　network　in　different　regions　to　be　self-contained.　Finally,　the　detected　communities　in　each　stage　can　be　divided　into　the　categories　of　monocentric　structure,　dual-nuclei　structure,　and　polycentric　structure　according　to　the　number　of　extracted　hubs.　The　polycentric　structure　is　the　dominant　mode,　which　shows　that　the　railway　network　has　significant　spatial　dependence　and　a　diversified　spatial　organization　mode.　This　study　has　great　significance　for　policymakers　seeking　to　guide　the　future　construction　of　high-speed　rail　lines　and　optimize　national　or　regional　railway　networks.　©　2018　by　the　authors.