An attempt is made here to estimate the correction, by the Brueckner theory, for nuclear quadrupole moment of the shell model. For simplest nuclei, as O-17, which consist of doubly closed shell plus an odd nucleon, the estimate may give some notion of order of magnitude. Assuming the model wave function to be the simplest shell model wave function, and ξ-function approximation for the effective two body potential, the correction can be calculated out. For O-17 the correctional term has the order of magnitude -1×10-26cm2