"I see it more as a challenge than pressure," he says. "I am confident about both the authorities and audiences, which I think are more open than before."

He knows he looks like Mao. He used to wear his hair long, and once when he pulled his hair back after taking a shower, he almost screamed upon catching a glimpse of himself in the mirror. Some of his friends even called him "chairman".

In fact, it was one of them, director Lu Chuan, who recommended him to Han Sanping, co-director of the movie.

But Liu has never essayed the role of a political leader. The good-looking actor has played postman, prince and policeman but never a politician.

For the upcoming film, he did his homework, which included reading Ross Terrill's biography on Chairman Mao. He also took to heart an excerpt describing how Winston Lord, special assistant to Henry Kissinger, sensed Mao's strength of will as soon as they met in 1972.

"I am convinced that if I'd never met the man, didn't know who he was, and I walked into a cocktail party at which he was present, he would draw me to him by his power," the book quotes Lord as saying.

Liu went through pictures and documentaries to form his own impressions about the powerful statesman.

"At meetings, he is often not fully concentrating," Liu says. "He seemed to listen, while thinking of something else. He thought big."

Liu has seen films and TV dramas about Mao and is familiar with the stereotypical image - a confident man who always has everything under control and likes gazing into the distance, a cigarette held between his fingers.

"I just cannot act like that. It's very artificial," he says.

"Today's audiences want to see a real person, a vivid one that they can relate to."

In the film he plays a 20-something Mao, seldom portrayed before. Liu says he wants his character to capture what today's young audiences share with the youthful Mao, such as the pursuit of dreams, career ambitions and the yearning for love.

"From the very beginning, I've been told this film has to win over audiences," Liu says. "I am happy to see the change in patriotic films. Filmmakers now understand that if you want to convey a message in a film you must first make people want to see it."

In the film, which revolves around the founding of the Communist Party of China in 1921, Mao is a charming young man enthusiastically exploring a path for the country out of the chaos following the end of imperial rule.

Unlike in previous patriotic films and TV series, Liu's Mao is slim and does not smoke. When the farmer's son first arrives in Beijing in 1918 after a long trek from South China, he is expelled from a classroom in Peking University for his shabby clothes.

He works as a librarian in the university and dates Yang Kaihui, later his wife. There are scenes dealing with their romance that bring to mind South Korean TV dramas and their romantic storylines and dazzling settings.

On a New Year's Eve, when Yang accompanies Mao on his nightshift in the library, there is a burst of fireworks outside. Mao hoists Yang up on his shoulders to see them.

"I am prepared for the controversy over my performance," Liu says. "Some elderly people, who are used to the old-fashioned portrayals of the leaders, may dislike me. But I believe young people will bond with my role."

This is the only time he will play Mao, Liu says, but denies it is because of the pressure or challenges.

"It's been a very exciting experience, but Mao is such an influential character that if I play him again and again, I might get stereotyped," he says. "As an actor I want different roles."