China
The Chinese were by far the top trader on the Silk Road, although they didn't intend for it to happen. China wanted information on the outside world, so rulers sent out certain people to investigate other cultures. But some of these investigators traded their knowledge of silk making and gave away one of China's most well kept secrets. However, this opened up new trade possibilities for China. China began officially trading silk for goods from other regions. This was such a big event, it gave the Silk Road its name.
India
India was well known for it's woolen carpets, curtains, blankets and rugs. Their craftsmanship impressed the Chinese, who were unfamiliar with their techniques. India was also known for their silver and semi-precious stones.
Europe
Europe traded everything from spices, glass, gold, and other precious metals. Europe often received goods from Egypt and recirculated them. Eventually, Europe started trading cattle and slaves on the Silk Road. With their variety of exports, Europe quickly made a name for itself.
Rome
Rome did not have many exports on the Silk Road, most of their involvement was through imports from the Silk Road. Rome was still not a large part of the Silk Road despite their imports.