Factory or fantasy?

Three of the four characters are "flowers of the factory" (the most charming women) in three eras - 1960s, 80s and present-day China. The other is a nostalgic middle-aged worker.

The film has had a mixed reception since its premiere at the 2008 Cannes Film festival and its fund-raising screening in Beijing for the Sichuan earthquake victims.

While some viewers called it a grassroots classic, others rated it as no more than a promotion for the real estate company that built the 24 City apartment complex.

Jia admits the real estate company paid one third of the 9 million yuan ($1.3 million) it cost to make the film but denies it is a shameless plug.

"The upheaval, from a big State-owned factory to an apartment complex, is an excellent example of the social transformation China has been experiencing in recent decades," he says.

As in Jia's previous films, the relationship between changes at a macro level and their influence on individuals' lives is a key theme.

"There are two main traditions in filmmaking history," he says. "One is to present fantasy, like The Impossible Voyage. The other, like the Lumire Brothers' Workers Leaving the Lumiere Factory, follows common people with down-to-earth cinematography. I think we need more of the latter nowadays."

Jia has balanced the film's budget by selling its copyright to more than 30 countries but says he still cares about its success in his home country.

"I will not be marginalized just because I make independent films," he says. "I care about the box office very much. Nor do I think this is a difficult film. It allows people to relate to their collective memory of the past 50 years, during which we experienced great social changes together."

Jia's next project will be a documentary, tentatively named Legend of Shanghai, on the city's last 100 years.