SHANGHAI—For weeks now, the number of Chinese visitors to Hong Kong has swelled with a brand-new category of tourists: moviegoers.

In a response to the censoring of a film during the Second World War by the Taiwan-born director Ang Lee, mainland movie fans have flocked by the thousands to Hong Kong to see the full, uncut version of the film, 「Lust, Caution.」

The phenomenon has highlighted the public's rapidly changing attitudes toward the long unquestioned practice of government censorship of the arts.

Travelers have made their way to Hong Kong to see movies before, of course, but always in much smaller numbers. Critics and commentators here attribute the interest in Mr. Lee's movie to a variety of factors, from word of mouth about risqu content stripped from the censored version, to a sensitive political subtext rarely seen in mainland cinema, to the fame of the Academy Award-winning director.

Perhaps most important, though, is the rise of a class of affluent urbanites in China's rich eastern cities who have grown increasingly accustomed to ever more choice in their lives.

At least one Chinese movie fan has tried to sue the State Administration of Radio, Film and Television, which regulates the industry, for deleting some of the film's content. Mr. Lee has said that the censored material was regarded as politically unacceptable in Beijing because it reinforced the notion of sympathy between a young Chinese woman and a collaborator with the Japanese occupiers. The lawsuit has been rejected by Beijing courts.

Many in the Chinese film industry support the idea of introducing a ratings system like the one used in the United States, which advocates say would lessen the need for outright censorship. The state film administration, however, has resisted.

People in the movie industry here said that the fact that a censored 」Lust, Caution」 was available at all in mainland China demonstrated how far the parameters of the acceptable had broadened since the beginning of China's reform era over two decades ago.

While many have been drawn to 「Lust, Caution」 by the allure of sex scenes, still more groundbreaking for a film here is the notion of a traitor in a leading role depicted as an attractive character instead of a villain.

「The country has undoubtedly be come more and more open and advanced, and it is the tide of history, which no one can prevent,」 said Fang Li, a leading producer. 「Compared to a market economy that's developing so fast, I've never seen an industry in China as backward as the film industry, though.」

Mr. Fang said much of the blame for this lay with the censors, a group of mostly elderly people who invite critical comment on movies from different branches of government, all seeking to present their constituency in the best light and to avoid offense. The censors 「spend most of their time worrying how not to lose their post,」 he said. 「They are very careful not to make mistakes.」