The principle of linking up school with life is the basic principle on which the socialist school is being built. If we judge the realization of this principle in general terms, technical education has many specific features. These appear far more strongly in the two subordinate principles — the principle of linking up education with productive work and the principle of polytechnic school. These two principles are highlighted by the author. In analysing the secondary technical schools sector we meet with difficulties arising from the great number of types of technical schools; there is a considerable number of study branches and a very many subjects. In a general analysis it is therefore impossible to analyse individual subjects, but we must deal with general characteristics, with fundamental features. The author points out that the requirement that education be linked up with productive work was pronounced by K. Marx already. At secondary vocational schools productive work and equivalent work in the services sector is realized in four ways (both alternatively and cumulatively): 1. in school workshops, 2. in the so-called special purpose establishments attached to schools, 3. in factories, 4. in other workplaces outside school. Having analysed the curricula of individual branches of study, the author comes to the conclusion that they comply with the principle of linking up classroom instruction with productive and other practical work, even though this link-up is being realized in various ways and not to the same degree. By giving examples from the present-day developments in some industries the author shows that the polytechnic process is already going on in production itself. In the field of vocational training it has therefore become an objective necessity. In secondary technical schools with a technological bias this is realized primarily by the current teaching material from engineering and electrical engineering. However, technology is penetrating more and more into non-productive spheres as well. This tendency is reflected in the teaching material of a technological nature even in some non-technological branches of study. From this analysis the author draws then a general conclusion: The content of education at four-year full-time secondary vocational schools puts into effect the leading principle of a socialist school — the principle of linking up school with life, as well as two subordinate principles, viz. the principle of linking up education with productive or other practical work and the principle of the polytechnic school. The realization of this principle will be further deepened in accordance with the guidelines set forth by the Communist Party of Czechoslovakia which are developed and concretely specified in the document of 1976, entitled „Further Development of the Czechoslovak Educational System“.