Bonding　in　structured　soil　limits　the　relative　motion　between　soil　particles　as　deformation　develops　with　loading.　This　makes　the　structured　soil　behave　differently　from　the　reconstituted　soil.　Based　on　the　unified　hardening　(UH)　model　for　overconsolidated　soils,　a　new　model　is　proposed　to　describe　the　stress-strain　relations　of　structured　soil.　The　new　model　is　developed　from　the　following　aspects:　(a)　a　moving　normal　compression　line　(MNCL)　paralleling　to　the　traditional　normal　compression　line　(NCL)　in　e-lnp　plane　is　proposed　by　introducing　a　structure　potential　parameter　to　describe　soil　structure　collapse　in　isotropic　compression;　(b)　a　moving　critical　state　line　(MCSL)　paralleling　to　the　traditional　critical　state　line　(CSL)　in　p-q　plane　is　proposed　by　introducing　a　bonding　parameter　to　describe　stress　ratio　evolution　influenced　by　bonding　in　shear.　This　parameter　is　adopted　in　the　dilatancy　equation　to　consider　the　bonding-dependent　dilatancy　of　structured　soil.　Both　of　the　above　2　structure　parameters　have　clear　physical　meanings　and　can　be　determined　or　estimated　by　conventional　tests.　It　has　been　analyzed　that　the　proposed　model　is　able　to　smoothly　and　continuously　reflect　the　positive/negative　dilatancy　and　strain　hardening/softening　of　structured　soil　influenced　by　bonding　and　its　decay.