The paper will explore the Muslim geographers’ understanding of China at the turn of the first millennium. The political and commercial expansion of the Islamic World during the ?Abb?sid Dynasty prompted the development of the field of geography beyond the inherited Greek, Iranian, and Indian traditions. The ?Abb?sid geographers began by locating the Islamic World at the center of the known world according to the basic framework of the earlier world geographic theories they assimilated. To this, they incorporated fresh contemporary information unknown to their Greek predecessors. The clear inclusion of detailed information about China, at the eastern edge of their known world, illustrates this process. The Muslim merchants who frequently sailed in the Indian Ocean to China during the ninth and tenth centuries returned to their West Asian homelands with valuable goods and abundant information about the societies they visited and often settled for long periods of time. These merchants and sailors gave substantial, detailed, and accurate information about China, its society, and its trade routes to professional writers like Ibn Khurrad?dhbih, Abu Zayd, and al-Mas??d? who collected, systematically arranged, and published this information for general readers during the ninth and tenth centuries. The world maps drawn by different geographic schools and individual geographers place most of Eurasia and North Africa with detail and accuracy and all locate China clearly at the eastern edge of the world. The paper will examine the close connection between the Islamic World’s flourishing contact with China, largely through the dhow ships that sailed directly between the port cities of Arabia and China during the end of the first millennium, and the increase in the Islamic geographical knowledge about the known world that transformed China from a Terra Incognita to Terra Cognita. This early description and depiction of China provided a crucial foundation for later works that further expanded that knowledge.