A self-consistent description of the MIT bag parameters as functions of the nuclear matter density is presented. The subnuclear degrees of freedom are treated in the Quark-Meson Coupling Model, considering the equilibrium conditions for the bag in the nuclear medium. The hadronic interaction is described in the framework of the quantum field theory of hadrons through several models. We have obtained the behavior of the bag radius and the bag parameters B and z₀ , taking their derivatives with respect to the mean field value of the scalar meson as free parameters. A discussion on the variation range of these derivatives is given.Facultad de Ciencias Exactas