For the first time in his 30-year acting career, Jet Li does not fight in a film.

Jet Li (right) plays father to an autistic son in Ocean Heaven. [China Daily]

In Ocean Heaven (Haiyang Tiantang), which opened the Shanghai International Film Festival, running until June 20, Li plays a marine park worker who desperately looks for a shelter for his autistic son after he is diagnosed with cancer.

Xue Xiaolu, a teacher at the Beijing Film Academy, wrote and directed the 7 million yuan ($1 million) movie.

The first-time director has been a volunteer for 14 years with Beijing Stars and Rain, a non-governmental educational organization for autistic children.

At first nobody was willing to take a risk on such a non-commercial script until film mogul Bill Kong, the man behind Hero (Yingxiong) and Crouching Tiger, Hidden Dragon (Wohu Canglong) stepped in.

Kong recommended the script to Li and asked him help the new director. After reading the story, Li said, "I will not only help her, I will act in the film".

The father's selfless love for his son touched Li, a father of four children himself. "I cried a lot when reading the script," Li says. "At the end the boy swims with a turtle and thinks it is his dead father, he cries, and I cried too."

"All parents feel very satisfied when their children make even a little bit of progress or give them back some care and love, but parents of autistic children get no such reward. With little hope, they are so courageous and accompany their children all through life," he says.

Li has not starred in any Chinese film since The Warlords (Tou Ming Zhuang) in 2007. Rather he has spent most of his time on his charity One Foundation, which has frequently been one of the quickest NGOs to arrive with aid at disaster areas and which is involved with many projects, including aiding schools for autistic children.

"I divide the films I do into four types," he says. "First, those that really touch my heart that I will do despite the budget and result; second, those I have to do because I owe some friends; third, for money; fourth, I have something to say, like in Fearless (Huo Yuanjia, 2006)."

He calls his new Hollywood flick The Expendables, in which he co-acts with Sylvester Stallone, a film for fun and money. "But Ocean Heaven is definitely the first type," he says.

Li helped gather a stellar cast and crew to work on the movie, including cinematographer Christopher Doyle, composer Joe Hisaishi and production designer Yee Chung Man.

When director Xue had any difference with the cinematographer or other crew on the set Li would support her. "A volunteer for 14 years, isn't that enough for trust?" he says.

Li says that when he was promoting the film in Hong Kong recently a journalist told him that after seeing the film, he hugged his father for the first time.

"This film shows that filmmakers have a responsibility to do something for society. If we can raise people's awareness of the issue of autistic children and their parents, that's enough."

The film will premiere on Friday.