Triaxial creep tests on CCG specimens were systematically performed using a self-made creep seepage experimental apparatus for determining the creep law of CCG. An improved triaxial creep model of CCG was established on the basis of a Nishihara model and another visco-elasto-plastic model, parameters of which were fitted on test data. Furthermore, the creep model is validated according to the result of triaxial creep experi-ments, and the outcome shows that the proposed triaxial creep model can properly char-acterize the properties of various creep deformation phases of CCG, especially the accel-erating creep phase. At the same time, the instability conditions of CCG were presented based on the discussion of the improved model\'s stability in terms of stability theories of differential equation solution.