A total of 35 miners were working underground at the privately-owned Jinshangou Coal Mine in Laisu Town, Yongchuan District, when an explosion shook the mine.
Fifteen workers were killed in the accident while two miners managed to escape. Eighteen others remain unaccounted for, Chongqing municipal coal mine safety inspection bureau said.
The bureau ordered all coal mines in the municipality to stop production and have safety checks, state-run Xinhua news agency reported.
The designed capacity of the mine is 60,000 tonnes of coal every year, according to its license.
China's mining industry has long been among the world's deadliest with frequent mine accidents.
China is the world's largest producer and consumer of coal.