China is the most populated country in the world, with over one billion people. It is home to several species of magical creatures, including the phoenix and the Chinese Fireball dragon (FB). Tibet is also located in China.
Two wizards of note were Chinese: magical creatures specialist Quong Po and alchemist Dzou Yen were both born there (fw).
China is also, presumably, the home of the Chinese Chomping Cabbage.
In 2010, China’s national Quidditch team played a spectacular three-day match against Moldova in the Quidditch World Cup. The final score was Moldova 750, China 640 (Pm).