Business networking site LinkedIn has launched a Chinese version, attempting to tap the huge market while navigating a strict censorship regime that has seen other foreign social media giants banned.
China has the world's largest online community with more than 618 million users.
But its "Great Firewall" blocks any online forums or content deemed sensitive, and it has barred access to Facebook and Twitter for several years.
Foreign technology firms must abide by strict rules to operate in the country. While the Chinese version of LinkedIn allows users to post public comments, unlike its English-language counterpart it does not currently allow group discussions.
LinkedIn pledged to be limited and open about its compliance.
"As a condition for operating in the country, the government of China imposes censorship requirements on Internet platforms," chief executive Jeff Weiner said in a statement on its website.
He promised that "government restrictions on content will be implemented only when and to the extent required" and that it "will be transparent about how it conducts business in China".
"LinkedIn strongly supports freedom of expression and fundamentally disagrees with government censorship. At the same time, we also believe that LinkedIn's absence in China would deny Chinese professionals a means to connect with others on our global platform," he said.
The company, which targets working professionals on the job market, said it was targeting more than 140 million Chinese users - nearly half its existing 277 million global members.
Its English-language version has been available in China for more than a decade, where it has attracted four million users, the statement said.
Foreign technology companies have faced challenges in navigating China's strict Internet controls, which are used to block expressions of discontent or other content that might undermine the control of the ruling Communist Party.
Yahoo elicited criticism in 2005 for allegedly giving the government details leading to the email account of a journalist who was later sentenced to 10 years' jail.
Google halted its mainland China search engine service in 2010 after deciding it would no longer censor results.
Facebook and Twitter were banned after they were used by protesters in the Middle East and North Africa to organise uprisings starting in late 2010 that overthrew longstanding regimes, in what became known as the Arab Spring.
Microsoft's Bing search engine came under scrutiny earlier this month following reports that Chinese-language searches for topics deemed politically sensitive by Beijing returned drastically different results to English-language searches - both inside and outside China.
Bing has denied censoring its Chinese-language search results outside China.
Domestic social media networks thrive in the country but face strict controls. Searches for sensitive terms are routinely blocked and offending posts are deleted.
China's Supreme Court ruled that month that Internet users could face three years in jail if "slanderous" information spread online was viewed more than 5,000 times or forwarded more than 500 times.
China's online population - defined as those who have used the Internet at least once in the past six months - is the largest in the world, having risen by 53 million in 2013 alone, according to the China Internet Network Information Center.