Studying the case of spherical quantum dot with parabolic confinement subjected to an external electric field with the presence of an impurity, the second and third harmonic generation suscepti- bilities have been calculated. The numerical method we are using for the calculation of the energy levels and the corresponding wavefunctions, is the potential morphing method in the effective mass approximation. As our results indicate an increase of the electric field and/or the position of the impurity and/or the quantum dot radius enhances the peak values of the second and third harmonic generation susceptibilities and redshifts the peak positions of their spectrum. Copyright © 2009 American Scientific Publishers.