Baidu has it's own search-tool, that's really meant for China and is only in Chinese. However it does index non-Chinese websites as well, e.g. searching for "android forums", does give this website at the top.
It's accessible internationally, but is subject to Chinese internet laws. google.cn in Beijing doesn't do search in the Mainland, and going to google.com for search redirects to google.com.hk in Hong Kong SAR. However this is sometimes blocked in the Mainland.
Bing does officially do a search-tool in China via cn.bing.com, which is subject to the internet laws and to comply with its ICP license.
ICP license - Wikipedia, the free encyclopedia
Baidu is the main search-tool for China, apparently 80% share. Just about all computers I've seen here have Baidu as the browser's homepage. When I bought my new Lenovo phone a few weeks ago, the default internet search was Baidu, and not Google or Bing.
AFAICT the vast majority of Chinese just never look at foreign sites. China has it's own home-grown equivalents to things like Twitter, Tumblr and Youtube, like Weibo, QQ Zone, Tudou and Youku.