Information relevant for demographic and social development is acquired through analysis of demographic structures and tendencies. In this paper, changes in the structural characteristics of Serbia's population in the second half of the 20th century are examined from the perspective of gender differences. The intention is to recognize marital, educational and economic characteristics as a dimension of the position of the sexes and gender relations from the perspective of the position and behavior of women and men. Gender differences of demographic structures are considered as a result of gender behavior models and as indicators of the state and position of women and men in concrete sociodemographic conditions. There are gender specificities of structural characteristics and their changes. The percentage of persons who never married is somewhat greater among men and celibacy is more characteristic of the male population (29.2% unmarried in 2002). Divorce is more frequent among women (4.8%) even though the percentage of divorced men rose in 2002 in relation to 1981 (3.1% in comparison to 1.9%). The main change in the education of women is the considerable increase of women with higher education (9.9% in 2002 in comparison with 0.9% in 1961), which is a greater change than in the population of men (12.3% in comparison with 2.7%). The effect of the change of men's behavior is shown through a smaller portion of highly educated men born in the late sixties and later in relation to older generations of men. The general percentage of economic activities is lower in both sexes, in 2002 in comparison with 1981, and it is more pronounced in the male population. The economic characteristics of the female population are still less favorable in comparison with the male population. The percentage of the dependant persons and those who do not work is greater among women than men between 30 and 40 years of age. Men with imperiled economic position are demonstrated with older men between 50 and 64 years of age, through the percentage of persons who do not have a job. The percentage of persons without a job is twice as much with men than women between 55 and 59 (19.6% in relation with 5.6%). The demographic picture of the changes in marital status, education and economic characteristic provides a framework to more profound analyses and empirical researches of gender inequality. It is necessary to thoroughly research socio-demographic determinations of gender differences and their changes. Position inequality and social sex disparity change with time but do not disappear. Gender inequality is continual, although the ways and degree of manifestation change. Researchers have a task to examine the interaction link of numerous factors of gender model behavior and to recognize the diversity of the aspect of the social position of women and men.