The earliest census in China was carried out during the reign of Emperor Ping Yuanshi 2 (AD 2) of the Western Han. The People's Republic of China has conducted six censuses (1953, 1964, 1982, 1990, 2000, 2010).
EAL carries a number of national and local census sources. They can be searched in PittCat. Here are selected samples -
There are special groups of people retrievable from PittCat such as -