This article presents additional data to better understand the history of intercultural communication between the Yenisei people and the Han Chinese. Although the mysterious history and isolated culture of the ancient Kirghiz (Chinese Xiajiasi 黠戛斯) tribes at the Yenisei River Basin are little known to the world, ancient Chinese books and the artefacts with Chinese characters, unearthed in the Yenisei region, present a vivid picture of the Yenisei people’s foreign exchange history. This article approaches the Yenisei–Chinese cultural interaction from the perspective of the Yenisei Turk-Runic language and the date of the E77 inscription. The research material for this study is the E77 Yenisei inscription that is engraved on a Tang Dynasty bronze mirror called the Sanlejing 三樂鏡 (Lobed Mirror of Three Delights). The authors’ interpretations of the local Runic language on the E77 Yenisei inscription reveal Yenisei people’s knowledge about the Chinese iconic figure of Confucius, which blends into the Tibetan Bon religion as Kong tse or Kong tshe. Therefore, this article confirms the culture contact between the Yenisei and Han Chinese people during the Tang Dynasty.