Texts are stated to have an important role in Turkish language education relevant to the goals stated in the Primary Schools Turkish Lesson Teaching Program and Guide (2006), and in the formation and improvement of the individual's reading culture. The aim of the study is to determine the comprehensibility levels of the texts in the Turkish language course books in Primary School 6th grade. Mixed (quantitative-qualitative) method is used in the study. In the study structured with mixed model, Sonmez Model is used to determine the comprehensibility levels of the texts in Turkish language course books. According to this model, the word level is determined by the division of the number of words in the texts by the total number of sentences in the texts. Difficulty levels is determined by dividing the number of foreign words, expressions, terms, concepts, metaphors, similes, symbols and formulas by the total number of words in the texts. Meaning levels is determined by dividing the number of foreign words, expressions, terms, concepts, metaphors, similes, symbols and formulas by the total number of sentences in the texts. The meaning level is divided by the word levels, and the comprehensibility levels of the texts are obtained by multiplying the result of this division by difficulty levels. The data being investigated in accordance with Sonmez Model, it is concluded that the texts in the Primary School 6th grade Turkish language course books are comprehensible and applicable in teaching environments. (Contains 4 tables.)