The main purpose of this research is to make students understand the reading texts more easily through substitution, which is one of the tools of text linguistics. As being one of the standards of textuality, Substitution helps to determine the semantic unity of lexical and linguistic relations, which take place among words, word groups and language units in the reading texts. Substitution directs the research focus on the objective of developing students’ reading comprehension skills, interpretation skills, inference skills throughout the texts. Nominal substitution, verbal substitution, clausal substitution and enunciative substitutions (Torusdağ & Aydın, 2017) based on utterances were determined through examining the coursebook, and they were shown with words and sentences they substitute. Document analysis and descriptive analysis were used as  a research method in order to examine the collected data (Yıldırım & Şimşek, 2017). The reading texts, which are found in the Secondary school, the fifth grade Turkish coursebook, were studied within the scope of substitution and effective reading comprehension. Briefly, substitution plays an important role at reducing word repetitions, developing reading comprehension skills, interpretation skills, finding main idea, answering questions related to the texts. When the components of substitution, nominal substitution, verbal substitution, clausal substitution and enunciative substitutions, were used appropriately, it shows that they improve the student’s competences such as comprehension, interpretation, finding main idea, asking questions about a text.  In conclusion, while conducting activity, a reading text, which included more clausal substitutions and enunciative substitutions based on utterances, was highly recommended for reading comprehension activities of narrative texts.