The purpose of this study is to explain the differences in the scope of grammar concepts in textbooks from the viewpoint of “consensus as an educational content”. For this purpose, we first refine the “educational content consensus index” and analyze grammatical elements. As a result, the grammar concepts were classified according to the degree of consensus. Moreover, using the binomial logistic regression analysis, it was confirmed that conventionality is one of the factors influencing the presentation of grammar concepts in textbooks. This study is significant in that it refines the concept of “consensus” and explores various ways of using the “educational content consensus index”.