Serving as jury president at the 12th Shanghai International Film Festival, Boyle told a panel discussion that it was "regrettable" that Beijing imposed restrictions on movies.
Chinese directors need to submit their scripts and their final products to censors for approval, with officials often demanding they cut politically sensitive and sexually explicit content. In recent major examples of censorship, Oscar-winning director Ang Lee was asked to edit his 2007 spy thriller "Lust, Caution" so it appeared less obvious the main female character betrayed Chinese activists who plotted to assassinate a Japanese-allied spy chief. Also in 2006, Chinese filmmaker Lou Ye was banned from making movies in China for five years after he screened "Summer Palace" at France's Cannes Film Festival without approval. Lou's love story was set against the pro-democracy student protests at Beijing's Tianamen Square in 1989, which the Chinese military crushed, killing at least hundreds.
"I know there are restrictions on filmmakers, which from our perspective, are regrettable. Great artists who work here _ and there clearly are great artists _ should be free. It's very important and valuable to the society that they are free," Boyle told a packed audience at a hotel ballroom in Shanghai.
But he added, "But for me personally, given an invitation to come and work here, I'd love to work here," joking, "It would be a challenge learning Mandarin."
Boyle also said he tried to shed an "imperialist" mentality when he shot "Slumdog Millionaire," learning from the experience of his 2000 Leonardo DiCaprio drama "The Beach," when he arrived in Thailand with 200 crew members.
"You are an army invading Thailand. You flatten everything in front of you. People just see you as money," Boyle said.
By contrast, he said he brought only 10 crew members from Europe to Mumbai to shoot "Slumdog," relying heavily on a local Indian crew, which he said worked better because Indian extras "won't react to the controlling instincts of the Western crew, quite the opposite _ the chaos just becomes more and more manifest the whole time."
He said he believes working with local crews is the future of Western films shooting overseas.
"The imperialist or colonial days _ you have to forget," he said.
Boyle said he also learned how not to view residents of Mumbai's slums patronizingly.
"All the values you bring that encourage pity in you towards the poor are actually redundant when you get there because they have these extraordinary communities living within the slums. They are very poor, visually, but they have this extraordinary resilience and self-support and sense of community," he said.
"Once you got over those feelings of pity that you had as an imperialist for someone poorer than you, you actually found things there to admire. It shifts the whole way you think about things," the director said.
"Slumdog Millionaire," the story of an orphan from Mumbai's slums who becomes the champion of the Indian version of "Who Wants to be a Millionaire," won eight Oscars in February, including best film and best director for Boyle, and made more than $350 million worldwide.