A number of things were traded in these exchanges; probably the most important was silk from China.
the silk road
Silk was important because it was worth lots of money from Asia.
By the time the middle ages were in full swing the silk road that had brought in the trade goods from China was gone. So, there was no trade between Europe and China in the middle ages. It was too far, took too long, and was too dangerous to make the trip. They got the silk from different kinds of animals.
Japanese impact on medieval Europe was minimal. Though the Europeans traded with China at times, and the Chinese traded with the Japanese, there was no direct route connecting Japan with Europe, and the indirect routes, such as the Silk Road, were not usually open.
Silk was traded for... i think gold :)
The merchants traded silk on the silk road
Spices and silk an porcelain/china
Samite was a luxurious and heavy silk fabric worn in the Middle Ages often with silver or gold threads
The item most traded on the silk road was gold and silk.
the qin dynasty traded many things like food, art, cutural ideas. one of the main things that they traded was silk. they usually traded silk to Europe in return of goods that china did not have access to grow or manufacure. they used the silk road for the trade
the Chinese traded silk for gold, silver and precious pebbles.