The　mechanical　properties　of　frozen　soils　are　significantly　affected　by　temperature　and　confining　pressure.　To　characterize　the　effects　of　temperature,　a　nonlinear　relationship　between　the　three-dimensional　tensile　strength　and　the　temperature　is　established,　which　is　incorporated　into　the　yield　function　based　on　the　coordinate　transformation　method.　To　characterize　the　effects　of　confining　pressure,　a　potential　strength　degradation　factor　is　established,　which　is　used　to　develop　the　hardening　parameters　that　effectively　account　for　the　effects　of　the　confining　pressure.　Finally,　based　on　the　framework　of　the　non-orthogonal　elastoplastic　model,　a　non-orthogonal　elastoplastic　constitutive　model　for　frozen　soils　that　can　consider　the　effects　of　temperature　and　confining　pressure　is　developed　in　the　coordinate　transformation　space.　Comparisons　between　the　model　predictions　and　the　triaxial　compression　test　results　of　the　frozen　silty　sand　demonstrate　that　the　developed　constitutive　model　can　simulate　the　stress-strain　relationship　of　frozen　silty　sand　under　different　temperatures　and　confining　pressures.　The　developed　constitutive　model　characterizes　the　temperature　effects,　i.e.,　the　increase　in　the　peak　shear　strength　with　decreasing　temperature,　and　the　confining　pressure　effects,　i.e.,　the　transition　from　shear　dilation　and　softening　to　shear　contraction　and　hardening　as　reflected　by　the　stress-strain　curve　under　the　increasing　confining　pressure.　©　2024　Chinese　Society　of　Civil　Engineering.　All　rights　reserved.