In the present paper a novel method for qualitative and semiquantitative analysis of the theoretical level of the transformation of scientific knowledge in school textbooks is outlined. These method, developed for the purpose of the investigation of the theoretical level changes of the curriculum in the course of the modernization of the theoretical conception oriented on the increase of the scientific level of the subject matter, has been submitted to test a sample of 30 textbooks in a model subject where a radical modernisation has taken place (as well in basic as in secondary schools). The paper briefly summarized the results of the research yielding evidence of some specific characteristics as well as of some more general features of the modernization trends. The conclusions to the method of research used imply a delimitation of its applicability for different types of comparative analysis.