Abstract：The creep tests of gypsum breccias are done；and the experimental creep curves and isochronous stress-strain curves are got，which display the properties of nonlinearity and accelerated creep. In order to describe these properties of gypsum breccias comprehensively，two viscous components of non-Newtonian fluid are put forward and are combined with conventional components to gain a new multiple rheological model. According to the new model，the corresponding one-dimensional and three-dimensional creep constitutive equations are deduced. Then the experimental creep curves are simulated using the new rheological model；and the results indicate that the new model can effectively describe the whole rheological process of gypsum breccias.
