The　performance　of　geogrid　reinforcement　is　largely　influenced　by　the　interlocking　effect　between　the　geogrid　and　soil.　To　enhance　the　performance　of　geogrid　reinforcement　in　sand,　a　novel　biocementation-enhanced　geogrid　reinforcement　method　was　proposed.　Biocementation　could　be　carried　out　in　situ　via　microbially-induced　carbonate　precipitation　(MICP).　To　understand　the　mechanisms　of　the　biocementation　enhancement　effect,　the　stress-dilatancy　behavior　of　coarse　sand　(CS)　that　was　treated　with　the　biocementation-enhanced　geogrid　reinforcement　method　was　studied　through　a　series　of　triaxial　tests.　The　test　results　showed　that　the　interlocking　effect　between　the　geogrid　and　CS　could　be　effectively　improved　when　the　CS　around　the　geogrid　was　biocemented　by　the　calcium　carbonate　(CaCO3)　that　was　generated　in　situ　through　MICP.　The　stress-dilatancy　behavior　of　geogrid-reinforced　CS　was　significantly　enhanced　after　biocementation.　In　addition,　the　interlocking　effect　that　was　provided　by　the　geogrid　could　mitigate　or　even　avoid　brittle　failure,　restrain　the　further　development　of　dilation,　and　enhance　the　mobilization　of　the　friction　strength　(q(f))　of　the　biocemented　coarse　sand　(Bio-CS)　during　shearing.