Bioretention　systems　have　been　widely　used　to　reduce　stormwater　runoff　pollution.　However,　there　are　few　researches　on　how　to　ensure　the　nitrogen　removal　performance　while　meeting　the　requirements　of　the　hydrologic　performance　of　the　bioretention　systems.　Formulated　soil　medium　is　a　key　factor　affecting　hydrologic　characteristics　and　nitrogen　removal　performance.　Therefore,　seven　bioretention　systems　have　been　constructed　with　different　formulated　soil　medium,　including　three　regional　guidelines　groups,　three　different　modifier　addition　groups,　and　one　control　group.　The　effects　of　different　formulated　soil　medium　on　hydrological　performance　and　nitrogen　removal　performance　of　bioretention　systems　were　evaluated.　The　results　showed　that　the　infiltration　rate,　water　retention　volume　rate　and　nitrogen　leaching　risk　could　be　significantly　reduced　with　the　silt　content　increasing　and　the　addition　of　modifiers,　while　the　moderate　silt　content　(10%)　had　excellent　NO3–N　removal　efficiency　(71.6%　±　19.8%).　AC　as　a　high-efficiency　soil　improver　can　be　reasonably　used　in　practical　projects.　Additionally,　it　was　found　that　the　capillary/non-capillary　hydrophobicity　of　formulated　soil　might　be　an　important　indicator　for　assessing　the　nitrogen　removal　performance　through　the　correlation　analysis　between　the　physical　and　chemical　properties　of　the　formulated　soil　medium,　hydrological　performance,　and　nitrogen　removal　performance.　It　is　difficult　to　achieve　the　best　hydrological　performance　and　nitrogen　removal　performance　in　the　bioretention　system　simultaneously,　thus　it　is　necessary　to　find　a　more　suitable　soil　medium　formula　to　balance　the　two　performance.　This　study　may　contribute　to　a　greater　understanding　of　the　influence　of　formulated　soil　medium　on　hydrological　performance　and　nitrogen　removal　performance　in　bioretention　systems.　©　2021