The official Xinhua News Agency said the morning accident occurred in a coal mine in Fuxin, a city in Liaoning province.
Rescuers were searching for four other miners who were trapped in the mine, Xinhua said, citing local authorities.
A spokesman at the Fuxin safety bureau confirmed that the explosion occurred early Thursday but would not provide further details.
The man, who refused to give his name, referred questions to the local coal mining bureau. A woman who answered the phone at the coal mining bureau hung up without answering questions.
China's coal mines are the world's deadliest, with numerous fires, floods and other disasters killing an average of 13 miners a day. Many accidents are blamed on small mines with low safety standards, or those operating illegally.
The government has promised for years to improve mine safety, but energy-hungry China depends on coal for most of its power generation.