You might think the traditional clothes of Chinese people are Tangzhuang and Qipao, but this is not the fact.
Han Chinese people had worn their own clothes - hanfu for thousands years before the invasion of Manchu army more than 360 years ago. During the establishment of Manchu-Qing dynasty in China, Han people were forced to give up their own clothes and shave the hair to be pigtail style. After Manchu-Qing dynasty was overthrown by Sun at the beginning of 20th century, the pigtail style hair was abolished, but Machu clothes was reserved because people could hardly remember their own colthes - hanfu. Nowadays, Manchu clothes have developed to be so-called Tangzhuang and Qipao, but they could not represent Chinese traditional clothes while Han people compose 92% of the total Chinese population.
There's a good news, more and more Han people wake up to the signality of traditional clothes, and start to redress the clothes which have been lost for more than 360 years by doing a lot of study through the history books and heritage. Of course, hanfu can hardly be dressed everyday in modern society, but on some important traditional festivals, it would be very nice and significative, just like the situation of kimono in Japan, you may find hanfu is similar to kimono because kimono was derived from hanfu in ancient China.
Here's a forum specially talking about hanfu:
http://c.1asphost.com/hanfu/forumYoung people dressed in hanfu: