Character building is an important component of 2013 Curriculum learning using textbooks as a learning source. This study aims to describe character values within the 2014 and 2017 revised editions of the 2013 Curriculum-based Indonesian Language Textbook for Year 10. The source of data for this research is the 2013 Curriculum Indonesian Language Textbook (BTBI) published by the Ministry of Education and Culture (Kemendikbud). Data in this study assume the forms of words, phrases, or sentences that indicate character values, collected by observation and note-taking and analyzed with a referential identity method. The 2014 and 2017 editions of BTBI carry the same character values, namely religiousness, nationalism, independence, gotong royong, and integrity. Differences in the character value content of both textbooks lie in the sub-values of each identified character value. According to the uncovered character sub-values, the dominant character in the 2014 edition of BTBI is independence. The 2017 edition contains three equivalent character values: religiousness, nationalism, and independence. Principles of Wasatiyyat Islam reflected in BTBI for Year 10 are values of tawassut (taking the middle way), tawazun (balance between the world and the hereafter), i'tidal (straightness and uprightness), tasamuh (tolerance), musawah (egalitarianism), shura (consultation), islah (reform), aulawiyah (prioritizing), tatawwur wa ibtikar (dynamism and innovation), and tahaddur (being civilized). These values represent the courteous, peaceful and gentle nature of the Indonesian nation.