This dissertation thesis focuses on the topic of the development of syntax of written Czech at the pupils of lower secondary education on the material of written compositions of story-telling. The thesis characterises the form of current syntax of written Czech and its development depending on the age of pupils. The analysis is bases on two collections of texts - the texts in the first collection were produced by 6th to 9th primary school grade pupils based in a town near Prague, the second collection was produced by 6th to 9th primary school grade pupils in Prague. These data were then supplemented with corpus material. In total, there were 302 compositions analysed. Moreover, to depict the reality in its complexity, also curricular and educational materials were being analysed as well as lesson observations and structured interviews conducted with teachers. The comparison between the particular constituents of written syntax enables the conclusions to be drawn being based on the analysed material giving evidence on the current state and development of written syntax with pupils of 6th to 9th grade of primary school, as well as possible disparities of development of particular syntax constituents to be identified and some recommendations for teaching methodology to be conveyed.