Prajñāpāramitāhṛdaya, which literally means the “The Heart Sūtra on Perfect Wisdom”, has been a widely disseminated Buddhist text in Greater China available in abridged and extended versions. While the most common abridged Chinese version was translated by Xuanzang in the seventh century, the extended version was first introduced to China and translated from Sanskrit into Chinese in the eighth century. Unlike the abridged version, the extended version adopts the format of a typical Buddhist sūtra and consists of an introduction (xu fen) followed by a main content section (zhengzong fen) and a dissemination section (liutong fen). This thesis focuses on the Chinese translation of the extended Heart Sūtra by Prajña and Satyacandra in 790 A.D., a largely uncharted territory in the field. Incorporating translation theories in Descriptive Translation Studies, including the norms theory, it investigates the translation of the Sūtra and its norms/causes from four major perspectives: 1) the initiation of retranslation of the Sūtra, 2) the organisation of the translation team, 3) the translation strategies of the Sūtra (Sanskrit-Chinese), and 4) the circulation of the Sūtra. This research not only reveals the interaction between the translation of the scripture and the factors of translation in medieval China, but also offers methodological innovation and new insights into Buddhist scripture translation in ancient China.