A systematical method which enables us to derive the phonon-quasiparticle interactions in spherical odd nuclei from the original nuclear Hamiltonian is developed from the standpoint of the microscopic theory. The fundamental idea is an extension, to the spherical odd nuclei, of the method which has been proposed by Marumori, Tokunaga and the present author with the purpose of analysing the “anharmonicity” on the collective oscillations in spherical even nuclei. In the conventional model of spherical odd nuclei, only one type of the interaction is assumed. According to our theory, however, we can find the existence of various types of the interactions some of which seem to have interesting physical meaning. It is not our purpose to go into detailed quantitative calculations, but rather to develop the basic idea.