Young parents of little kids may think they know their children, but they might not really know them. This is the opinion held by Professor Zhang Tongdao, who is also the director of a documentary film "Kids Kingdom". His production reveals the real world of kid's to adults, especially young parents.

On Tuesday afternoon, the Beijing's Youth Palace Theater was packed, mostly with young parents eager to watch a documentary film that records the lives of some children in a kindergarten in the suburbs of Beijing.

The documentary focuses on three kids, four-year-old Chen Chen, who waits in the yard for her friend Nan De every morning. Then there's five year old Chi Yiyang, who is the leader of a group of boys, and whose mischief is always the headache of the teacher. And two year old Xi Kun, whose strange behavior reveals his huge curiosity.

The documentary delves into delicate emotions, power to influence others, and curiosity about the unknown all in a "Kid's Kingdom."

Director Zhang Tongdao is a professor of Beijing Normal University and teaches documentary film. But fathering a child prompted him to shoot a documentary himself.

Director Zhang Tongdao said, “When my son grew to three or four years old, I began to ask myself how to treat him. There are two ways ready made, treat him like a pet, or treat him strictly like the traditional way. But I don't like either of these two ways. Then I watched two good documentaries about children, one from France "To Be and To Have", and the other from China "Kindergarten". Then I wanted to have a try, to shoot a documentary myself. But after I began to shoot the documentary at one of my friends' kindergarten, I found I didn't know children well.”

Zhang aims at revealing a real kids world when the kids' parents are not around. He and his colleague, cinematographer Liu Dedong, spent two years observing and recording the kids' lives in a kindergarten called "Ba Xue Yuan". They shot one-hundred-and-eighty hours of film, and clipped the most intriguing parts into the eighty-five minute documentary.

An audience said, “The film shows the very real world of kids. We don't know how our kids behave when they are in kindergarten. Actually, they are in a mini society in the kindergarten. The personality he or she forms at home will be brought with them when they are in a group.”

A forum centering on the documentary was held after the premiere. Experts in documentary film making, and pre-school education gave high praise for the production, calling it a project that both parents and child educators should watch.