Baidu (百度) is the Chinese Google. It dominates Chinese language search with about an 80% market share and is one of the biggest sites worldwide. As a local Chinese site it censors it's search results. Like Google, Baidu offers a number of services apart from search, including Maps, documents, MP3 search, Baidu Space (a social network with over 100 million users) Baidu Encyclopedia, (China's largest encyclopedia by users) and is launching a new video site called QiYi.com in March.
Kaixin001 (开心网) is one China's fastest growing Social networking sites (SNS) with 75 million users. It claims to be growing at a rate of 100,000 to 200,000 new user registrations per day Essentially a Facebook clone with applications, gaming, groups and pages.
Renren.com (人人网)is another social networking site similar to Facebook. and is a fierce rival of Kaixin001. Renren.com claims to have 200 million registered users. It mainly caters for college students, though it is actively looking to expand its reach.
Youku (优酷) was ranked #1 in Chinese Internet video sector in January 2010. Users can upload videos of any length and it's library includes many full length, popular films and TV episodes from the West as well as Chinese content. It's main rival is Tudou.com
Tudou (土豆网) is a video-sharing site and competes directly with Youku.com. Like Youku, users can upload videos of any length. Tudou serves over 100 million videos each day with more than 40,000 new videos published daily.
Tianya (天涯) portrays itself as the "King of the Chinese Internet community". Certainly it's BBS message boards are the most active in China. Every issue under the sun is debated, argued and posted here. Many Chinese internet memes start here and replies to posts can run into the thousands. More than 33 million people across China regularly visit the Tianya forum.
Taobao (淘宝网) is the Chinese Ebay. It is China's largest Internet retail platform , taking up about three-fourths of the market share. Nearly 50% of all Chinese Internet users are registered on Taobao. Alibaba's Jack Ma has said: “eBay may be a shark in the ocean, but I am a crocodile in the Yangtze River. If we fight in the ocean, we lose—but if we fight in the river, we win.”
Douban (豆瓣) is a popular Chinese social media site ( ranked 24th in China) with over 30 million unique users a month. It started about five years ago and has all the now common features of social media sites such as groups, the ability to "friend" others, etc.Douban users tend to be between 20-35 years old and single. Mostly into arts, films, music and culture. The CEO of the site Ah Bei claims that: "Douban has never been an SNS site; it has a community or social networking community. Perhaps it's a social network based on books, or on movies, but Douban is broader than that."
Douban has recently had a redesign, which adopts a Facebook style feed on the frontpage.
Sina (新浪) is reportedly China's largest "infotainment" portal and is third in terms of Traffic Rank within China, behind Baidu and QQ. Sina is popular for news, but also for it's blogs, which are some of the most read in the world. It recently launched a microblogging service (like Twitter) t.sina.com.cn. which has proved extremely popular (now the largest micro-blogging site in China) and is growing at a tremendous rate.