The triaxial compression creep test on concrete specimens of tunnel lining structure is performed by the MTS-815 hydraulic servo system. The stage of accelerating creep appears when the ratio of compression creep strength to compressive strength is about 0.85. A combined viscoelastic plasticity model is developed after the characteristics of concrete creep deformation were analyzed

which can be used to describe the creep behavior and whole creep process of the tunnel lining structure. The combined model is characterized by a visco-elastoplastic deviatoric behavior and an elastoplastic volumetric behavior. The viscoelastic constitutive law corresponds to the Burger model

and the plastic constitutive law corresponds to a Mohr-Coulomb model. The characteristics of viscoelastic plasticity can be described by the combined model. The problem which the typical Burgers model only can be used to describe viscoelasticity creep is resolved perfectly. In addition

the methods to solve triaxial compression creep model parameters are given and the parameters of tunnel lining structure are determined.