The study, from the statistical point of view, of empirical distributions, necessarily leads to the theoretical ones which generate these last and permit to understand them. In Social sciences, there are relatively few theoretical laws elected. The most known are the law of Laplace-Gauss, the exponential law or the one of Gibrat (Lognormal). Here, we want to see how much the Pareto's law contributes to the study of certain social phenomena like the inequality in the distributions of socio – economic wealth. The law of Vilfriedo Pareto is still little used in this area. Yet, there is evidence (BROT Mandel, 1973; BARBUT MARC, 1989) that the distribution of many natural phenomena or socio –economic can be represented by such laws. They fit better when we have to discuss issues relating to the allocation of goods and services. Indeed, it appeared that the functions of Pareto's type provide a good representation of phenomena characterized by asymmetric distribution. We must remember that Pareto discovered this function when he was exploring the distribution of wealth in his country. Here, by considering the results found about the Pareto's law, we want to study the distribution of income regarding their concentration and components. We insist on the graphic representation to compare the distribution of income according to their courses and geographic regions.