According to state media on Tuesday, the blast in Fuxin city is the worst mining disaster in the country's recent history.
Thirteen others are trapped underground while 22 workers were injured in the Sujiawan colliery in Liaoning province, the official Xinhua news agency said.
Mining accidents and fatalities are an almost daily occurrence in China but they are getting more severe amid a booming demand for fuel to drive China's runaway economy.
Two deadly accidents last November claimed more than 300 lives between them.
Critics and miners say lives are being sacrificed in the quest for energy.
China's coal industry, the most dangerous in the world, saw more than 6000 workers die in mining accidents in 2004, according to official figures.
But labour rights groups say the real number of fatalities could be around 20,000 annually as many accidents are unreported to keep mines open and avoid costly fines for fatalities.