This paper aims to compare and analyze the text complexity of advanced Korean and Chinese textbooks, focusing on their quantitative factors. In particular, it analyzes the text complexity of advanced textbooks used in Korea and China in terms of vocabulary difficulty, sentence length, and sentence complexity. The analysis, shows that the vocabulary difficulty of volume two of the advanced is higher than volume one, but this is reversed in the Chinese textbook. In the Korean textbooks, the sentence lengths were longer in advanced volume one than in volume two, whereas Chinese textbooks, had shorter sentence lengths in advanced volume one than advanced volume two. Finally, in terms of sentence complexity, the Korean textbooks had more complex sentences and are therefore more difficult than Chinese textbooks in all its the advanced volumes. The analysis of the vocabulary difficulty, sentence length, and sentence complexity factors shows that text complexity increases with the level of learning in Korean textbooks. In Chinese textbooks, this is generally reversed, which makes it more difficult for learners using advanced volume one than advanced volume two.