A formula is given for the electrical resistivity of metals with the use of the result of excitation-response theory. It is shown that the electrical resistivity is expressed in terms of the four-dimensional Fourier transform of the appropriate pair correlation function in space and time of the scattering systems, by which conduction electrons are scattered to lose their initial velocity. The dependence of the electrical conductivity on the effects of the correlation in the scattering system is discussed systematically by using the correlation functions in some of the typical examples. Especially the electrical resistivity of the ferromagnetic metals is discussed in some detail by using the so-called s-d interaction model. In this case it is shown that the inclusion of the effect of the correlation between d spins gives rise to deviations in electrical resistivity from the one given by the simple molecular field approximation.