Codswallop. Marco Polo's father and uncle had been to China before him; Venetian and other Italian traders had dealt in Chinese goods for centuries. Marco Polo was the just the first to write about it, exposing his travels to a wider audience. However, the popularity of his book also has to do with the fact that he made a lot if things up (admittedly, he also did some fairly remarkable things when he was there).

Further, as posters have noted below, some, sporadic knowledge of China had existed since Roman times.

The Romans where aware of the Han Dynasty and traded Silk, wine and olive oil. What they knew about each other was limited by the sheer distance that separated them. The western Roman Empire probably did little trade with China the parts of Rome closer to Persia probably did most of Rome's trade with China.

A map of the world by Ptolemy, in the east of the map is "Sinae" China.

Chinese description of Rome and there products.

Also check this question out http://www.reddit.com/r/AskHistorians/comments/2306e8/just_read_the_faq_got_intrigued_by_contact/