The aim is to study the fundamental constitutive relations for describing the behavior of geomaterials, formulation and explanation of the basic principles of individual relationships, identifying their material characteristics and possibilities of their applications in mathematical models. Students are familiarized with basic models of linear and nonlinear elasticity and with more advanced constitutive models based on the theory of plasticity. Partial order is also the formulation, analysis and mutual comparison of rheological models. Student should be able to after the course to evaluate the suitability of a constitutive relation for the type of geological environment, characterized by the input data of the constitutive law and apply the model behavior in the corresponding mathematical model.