In order to evaluate the stress-strain behaviour of isotropically and/or anisotropically consolidated cohesive clay, two different types of isotropic hardening critical state models and an anisotropic hardening critical state model were developed based on the critical state concept and the new assumptions of the internal work dissipated per unit volume of soils. The model proposed is based on the associated flow rule, in which a set of yield function and hardening modulus are contained. It was shown that the models had the possibility to be able to reasonably represent the cohesive and anisotropic properties in stress-strain curves for normally consolidated clay.