The persistance of social homogamy is regularly observed; the tendency to form couples in which the woman occupies a lower position than her partner – female hypergamy – is also well documented: love is far from blind to social distinctions. Yet, it was concluded somewhat too fast from this major result that these phenomena have remained stable over time.This thesis shows, based on large-scale survey data, that education, social class and social class of origin homogamy has significantly weakened over the last forty years in France. This trend goes beyond what changes in the population structure would have implied (relative homogamy): the composition of couples has become closer to a random mating situation.Hypergamy has also clearly diminished, and has even reversed regarding education; females hold higher qualifications than their partners since the year 2000. As a consequence, the higher celibacy rate of women with a high social status, in particular that of the higher educated, which stemmed from their unfavorable position on the conjugal market, has converged to that of other groups.The variations of these two dimensions of partner choice over 64 regions of Europe in the 2000s are also sizable. Educational homogamy is higher than socioeconomic homogamy; hypergamy is the most frequent situation, but it is not an absolutely general pattern. The degree of cultural liberalism and of social openness appears as the strongest determinant of these two phenomena. They are negatively correlated with female labor force participation, but their relationship with economic inequalities is ambiguous.