Previous　tests　on　introducing　N-(N-butyl)　thiophosphoric　triamide　(NBPT)　to　microbially　induced　carbonate　precipitation　(MICP)　process　achieved　a　certain　positive　result.　Further　study　about　applying　NBPT　to　sand　column　tests　with　MICP　method　was　carried　out.　Some　test　methods　such　as　the　unconfined　compressive　strength　test,　product　content　detection,　scanning　electron　microscope,　energy　spectrum　analysis　and　X-ray　diffraction　test　were　conducted.　An　in-depth　study　on　the　reaction　products　was　conducted　and　the　effect　of　NBPT　on　the　formation　of　calcium　carbonate　by　MICP　reaction　was　analyzed.　The　results　show　that　the　participation　of　NBPT　in　MICP　reaction　has　a　regulatory　effect　on　the　morphology　and　size　of　CaCO3　crystals.　When　the　concentration　of　NBPT　is　not　higher　than　0.1%,　the　formation　of　calcite　micrograins　is　controlled.　When　the　concentration　is　between　0.1%　and　1%,　the　products　coexist　with　calcite　and　vaterite.　When　the　concentration　is　higher　than　1%,　almost　all　crystals　are　vaterite.　In　addition,　NBPT　is　involved　in　the　formation　of　organic　precipitates　that　form　copolymeries　with　calcium　carbonate　crystals,　which　contributed　to　the　bonding　effect　of　MICP　reactions.　©　2022,　Editorial　Board　of　Journal　of　Huazhong　University　of　Science　and　Technology.　All　right　reserved.