The most popular activity done during the Dragon Boat Festival is the racing of Dragon Boats.
Qu Yuan (343–278 BC), who was named Ping, but styled himself Yuan, was a Chu State official in the Warring States period. He was the earliest famous poet in China. See Qu Yuan Ancestral Hall and learn more of Qu Yuan.
When the Chu capital fell the patriotic poet drowned himself in the Miluo River. The local people were said to have paddled out on boats, either to scare the fish away or to retrieve his body. The dragon boat races represent the attempts to rescue and recover the body of Qu Yuan. This is said to be the origin of dragon boat racing.
The custom of dragon boat races probably began in southern China, where the 5th day of the 5th lunar month was a totem ceremony. The dragon was the main symbol on the totem, because the Chinese are said to be the sons of the dragon. They also made dragon-like canoes.
Later Chinese connected this custom with Duanwu Festival. Since this custom was only practiced in southern China, this might be why dragon boat racing isn't that popular in other parts of China today.
Now dragon boat racing is an international event. This sport is popular in the USA, Canada, Europe, Australia, Taiwan, Hong Kong, and Singapore. Some dragon boat races aren't held around the Dragon Boat Festival. Some are in July, August, or September. You need to check their websites for the schedules.
China Highlights can help you design a tour to see a dragon boat racing and other highlights of China.