The paper discusses a rate-dependent constitutive model to describe the creep deformation of rock salts. The model is based on the dislocation-related micromechanisms; the concept of effective stress is utilized by incorporating the back stress as an, internal variable The model is used to predict the creep potential of rock salt under general thermo-mechanical loading. The experimental test results from Avery island dome salt are used in this work. The associated five model parameters are evaluated by using an. optimization technique, called ＇＇box algorithm.＇＇ The parameters are then used with the model to predict unoptimized experimental data sets. The influence of temperature and confirming pressure are investigated in detail for the selected rock salt. Overall, excellent correlations are observed.