Results of the research of social cohesion in Czech society, from the point of view of mechanisms of the reinforcing, social stratification and the role of the welfare state. Includes special studies about the vertical and horizontal dimensions of the social differentiation as a reason of the social cohesion and social anomy. (Differentiations at education, employment and anemployment, activitis on the labour market and economy, at the branches, in incomes and in ownership, in regions, in ethnical and gender diferentons and so on.) This is the first study of this type in the Czech scientific literature.