Park bosses got the idea from an art installation in Germany where sculptor Fabian Brunsing created a similar bench as a protest against the commercialisation of modern life.
"He thought he was exaggerating. He didn't foresee that a very practical country like China might actually use them for real," said one critic.
Parks in China suffer from chronic overcrowding at weekends when millions of people try to escape the country's teeming cities.
"We have to make sure the facilities are shared out evenly and this seems like a fair way to stop people grabbing a bench at dawn and staying there all day," said one park official.