With the advancement of the tools for the analysis of reinforced concrete structures, a proper understanding of the applicability and limitations of the constitutive models has become imperative. This paper lists some of the models that are used for plain and reinforced concrete. The models are presented according to the states of uniaxial, biaxial and triaxial stresses. For reinforced concrete panel elements subjected to shear, models incorporating the softening of concrete compressive stress and the Poisson's effect in the steel tensile stress, are emphasised.