This book explores the history of foreign astral science in China from the unique viewpoint of the knowledge introduced to the Middle Kingdom by monks, travellers, and merchants from different parts of Eurasia throughout the first millennium CE. By comparing the extant works in Chinese with parallel materials in their original languages, including texts in Sanskrit and Pali for the Buddhist materials, and in other languages for works by the Nestorians, Zoroastrians, and Manicheans, this book fills a lacuna in the understanding of the role foreign scientific ideas played in Chinese and East Asian societies. Including full English translations of a number of Chinese texts of foreign origin for the first time, together with commentaries and the critically edited original Chinese texts, this book will appeal to students and scholars of the history of science and Chinese history.