The Book of Later Han by Xie Cheng (Jin Dynasty)

Chinese ancestors had since the late Han Dynasty (206 BC-220 AD) at the latest been engaged in fishing and other production activities in the South China Sea.

Chinese ancestors had begun tapping the resources of the South China Sea since the late Han Dynasty at the latest, when it was already a main channel for communication between China and overseas. It is recorded in The Book of Later Han, compiled by Xie Cheng in the Jin Dynasty (AD 266-420) that "All contributions from the seven states in Jiaozhi are shipped in through Zhanghai." This indicates that taxes paid by the seven states of Jiaozhi were primarily sent to the central government via the sea route.