We　propose　a　hypoplastic　model　to　capture　the　short-term　and　long-term　creep　behavior　of　granular　material　by　incorporating　grain　breakage　and　wetting　effect.　In　the　proposed　model,　the　variable　critical　state　line　is　adopted　to　assess　the　effect　of　grain　breakage　on　the　strength　and　deformation.　In　addition,　a　piecewise　degradation　law　for　the　creep　deformation　is　adopted　to　evaluate　the　wetting　effect.　The　proposed　model　is　verified　by　predicting　a　series　of　laboratory　tests.