The Communist Party of China (CPC), also known as the Chinese Communist Party (CCP), is the ruling political party of the People's Republic of China and also the world's largest political party. This status as ruling party is guaranteed by China's constitution, regardless of what the popular vote of China's citizens might be. With more than 70 million members, the CPC is the largest political party in the world, with this number being but 5.5% of the total population of China.

The People's Republic of China (PRC) is formally a multi-party state under the leadership of the Communist Party of China in the popular front model similar to the former Communist-era Eastern European countries such as the National Front of Democratic Germany. The dominance over the political system is such that China is effectively a single-party state.

For details:

http://en.wikipedia.org/wiki/List_of_political_parties_in_the_People%27s_Republic_of_China