The Tang (618-907 CE), Song (960-1279 CE), and Yuan (1271-1368 CE) periods witnessed a dramatic increase in the number of foreign medicinal ingredients entering China's written materia medica from abroad. Many ingredients that would emerge as essential to Chinese pharmacology by the Ming period (1368-1644 CE) were imported in these earlier centuries by sea at China's southern coast, and represent contributions of traditional medical systems from afar. An analysis of medicinal and organic materials recovered from shipwrecks dated from within this transition reveals a dynamic network of long-distance trade relationships that informed traditional Chinese medical practice. Examining recovered materials including star anise, Chinese olive, and multiple aromatic tree resins from the Belitung, Intan, and Java Sea shipwrecks within the evolution of Chinese materia medica and records of long-distance trade illuminates the role of the maritime trade routes in the Southern Ocean as China's premodern Medicine Road.