
Archaeologist Liu Qingzhu of the Chinese Academy of Social Sciences was quoted as saying the room is unlike any ever found in a Chinese tomb.
"Qin himself was very unusual, so it's not unexpected that his tomb should also be unique," Liu told the news agency.
Archaeologists theorize that because the room was built on top of Qin's mausoleum and seems to have ladder-like steps leading up, it was intended as a passageway for his spirit, Xinhua said.
Qin is credited with starting construction of the Great Wall and commissioning an army of terra cotta soldiers to guard his tomb.
Thousands of the terra cotta warriors were discovered more than 20 years ago by peasants from a local commune who were sinking wells.