Microbially　or　enzyme　induced　carbonate　precipitation　has　emerged　to　be　a　new　type　of　soil　improvement　method.　However,　it　appears　that　the　biocementation　process　is　affected　by　many　factors　and　a　common　understanding　on　the　control　factors　on　the　biocement　effect　has　not　been　reached.　This　paper　attempts　to　identify　the　main　factors　that　controlling　the　MICP　or　EICP　effect　through　an　in-depth　discussion　on　the　fundamentals　of　biocementation　process.　Similar　to　other　cemented　granular　materials,　biocemented　soil　is　a　structural　soil　composite　consisting　of　soil　skeleton　and　biocement　force　chain　or　biocement　network.　The　strength　and　stiffness　of　the　biocemented　soil　is　controlled　by　the　reinforcement　effect　of　the　biocement　network　on　the　soil　skeleton　or　the　interplay　of　the　soil　skeleton　and　precipitates.　The　contribution　of　the　strength　by　soil　skeleton　is　affected　by　the　soil　types　and　soil　properties,　while　the　contribution　of　the　precipitates　is　through　the　distribution　of　the　biocement　network　and　the　properties　of　the　precipitates.　©　2024