China’s biggest online video streaming site, Youku.com, has paired up with Warner Bros. to stream “Inception” to Chinese webizens — the latest sign of increased sophistication in the world’s fastest-growing movie market.

Youku.com will stream the movie through its Youku Premium on-demand service, which allows Internet users to watch it on various devices, including cell phones, a hugely popular way of catching movies in China, where there are now 450 million Web users.

Youku.com is effectively China’s answer to YouTube, which is banned in the country. Although it’s primarily a site for user-generated content, Youku has increasingly turned to premium content to broaden its appeal.

In December, it listed on the New York Stock Exchange. The stock rose 161% to $33.44 on the first day of trading, the biggest gain for a U.S. initial public offering in five years.

“Through building long-term partnerships with copyright holders and communicating with our media partners, Youku Premium is creating a whole new way for people to find and watch the content they want, when they want it,” Youku founder and CEO Victor Koo said in a statement.

“Inception” made $69 million during its theatrical run in China, according to figures from the State Administration of Radio Film and TV, and the China Film Distribution and Exhibition Assn.

Youku has set up a dedicated page for “Inception” where, as well as watching the film anywhere, users can interact.

China’s film market is booming. The box office for 2010 is expected to exceed $1.5 billion, up 65% on the $910 million reported in 2009.