Chinese archaeologists have found thousands of official files from over 2,000 years ago.
The 20,000 ancient bamboo slips have details about the political, economic and cultural life of the Qin Dynasty (221-206 BC).
The information on the bamboo slips includes details about army food consumption and relations between different ethnic groups.
Xinhua says they were unearthed in southern China's Hunan province.
Experts are comparing the find to that of the Qin Dynasty terracotta soldiers and horses unearthed in Shaanxi province in the 1970s.
Researchers say only 2,000 bamboo slips were unearthed during the last century.
Guo Weimin, deputy director of the Hunan Provincial Archaeological Institute, said: "This is the first time that such a huge amount of bamboo slips recording history ranging from the Spring and Autumn Period (770-476 BC) to the Western Han Dynasty (206 BC-AD 25) has been found in China."