The Romans have an idea that China exists, but their notions of it are extremely vague. The world in both Latin and Greek for Chinese is seres (Σῆρες), literally, the people who produce silk sericus (σιρικόν). The Romans also knew the Chinese were extremely far away. When mocking a gossip-mongering woman, Juvenal writes that "she knows what the Chinese (Seres) and Thracians are up to." (Juv. 6.403).

Distance and silk production are about where popular knowledge of China ended in Rome. The geographer's knew a bit more. The first century AD Periplus of the Red Sea (a guidebook to ports in the Indian Ocean) knew that silk came from a place beyond India, a great city called Thinae. Strabo thinks the Chinese may have been exceptionally long lived (over 130 years), and dwelt beyond Bactria (roughly modern Afghanistan)(Strab. 11.11.1; 15.1.34). Pausanias thinks the Seres lived in an island in the Indian Ocean, or perhaps on an island in a river that emptied into the Indian Ocean. They were according to him either a branch of the Ethiopians, or perhaps descendants of the Indians and Scythians (nomads from Central Asia) (Paus. 6.26.6-9).

You can see this doesn't amount to much, especially when compared to Roman knowledge of India, Arabia, or even East Africa. Politics are partly to blame for this: the relationship between Rome and neighboring Parthia was rarely cordial enough for Roman traders to be entirely comfortable with long overland trips across Parthia. This meant that any contact with China would have to be made by sea. But it was probably far cheaper and safer to simply buy Chinese goods from Indian ports than it was to venture further East. Economics limited Roman interest in China at least as much as politics did.