Building on the foundation of traditional philology (xiaoxue) and extending to multiple schools of thought, Zhang Taiyan's work On National Learning is a very important work in Chinese intellectual history. The seven essays on literature in its middle volume, which address such issues as literary and cultural traditions situated between the study of Chinese characters and philosophy, play a key role in the mainstream study of literature and culture. This article analyzes Zhang's idea of "writing based on Chinese characters" and his principle of "standardizing by Chinese characters" in literary criticism, as well as their significance to and function in the entire middle volume of On National Learning. It intends to, through such analyses, comprehend Zhang Taiyan's intellectual inquiry and cultural concern.