This paper accounts for why Chinese Buddhists believe that Nāgārjuna is the author of the Mahāprajñāpāramitopadeśa, the commentary on the Pañcavimśatisāhasrikā Prajñāpāramitā Sūtra. It refutes past theories on the authorship of the text which proceed from the perspective of Indian Buddhism, and proposes a new theory which ascribes the authorship to Sengrui's editorship that reflects the intellectual situation of Chinese Buddhism of the early fifth century. The authorship issue is actually of a historical event rather than a personal identity. For this new theory, the paper investigates the intellectual activities of Kumārajīva and Sengrui, the translation process, and compares terminological differences and textual variations between the old and new translations of the Sūtra and accompanied doctrinal explanations in the commentary.