China is the world's most populous country. So the biggest census precess will naturally be Chinese. Yes now China has started its once-a-decade census that will see six million census takers go door-to-door to document the massive demographic changes happening there. The data collection will conclude on November 10, with the the main data to be released at the end of April. According to the 2000 estimate China's official population is 1.295 billion people.
After years of reforms that have reduced the government's once-pervasive involvement in most people's lives, some Chinese may be reluctant to divulge personal information, harbouring suspicions about what the government plans to do with their details. Another complicating issue are children born in violation of the country's one-child policy, many of whom are unregistered and therefore have no legal identity. They could number in the millions.