For more than 20 years the science teachers, the researchers in science education, the educationists and the other pedagogues have been acquainted with the model of educational reconstruction. In this model there are integrated three areas of this scientific interest: the recognition of pupils’ conceptions, the investigation of scientific conceptions with didactics branch approach and the creation of an educational content (Duit, R., Gropengießer, H., & Kattmann, U. (2005). Towards science education research that is relevant for improving practice: The model of educational reconstruction. In H. E. Fischer, (Ed.), The Developing standards in research on science education (pp. 1–9). London: Taylor & Francis; Duit, R., Gropengießer, H., Kattmann, U., Komorek, M., & Parchmann, I. (2012). The model of educational reconstruction – a framework for improving teaching and learning science. In D. Jorde & J. Dillon (Eds.), Science education research and practice in Europe. Cultural perpectives in science education, 5 (pp. 13–37). Rotterdam: Sense Publishers; Kattmann, U., Duit, R., Gropengießer, H., & Komorek, M. (1997). Das Modell der Didaktischen Rekonstruktion – Ein Rahmen für naturwissenschaftsdidaktische Forschung und Entwicklung.Zeitschrift für Didaktik der Naturwissenschaften, 3(3), 3–18). There is required to reconstruct the educational content for learning and teaching purposes. It leads to the educational structuring and to the clarification in scientific field. Therefore, in this contribution there is analysed a formation of the concept chemical reaction from the perspectives of the chemistry textbooks used in the 19 th , the 20 th and the 21 st centuries in Slovakia. These findings could be useful in the process of comparison between scientific and pedagogical knowledge in this branch not only in neighbouring countries, even in the broaden European or worldwide content.