The blast occurred around 3 pm yesterday at Niulanchu Coal Mine in Hunan Province, state-run Xinhua news agency reported.
Six miners died on the spot and one was injured seriously and sent to a local hospital.
Rescuers are still searching for one more miner who went missing after the blast, authorities said.
An initial investigation showed that mal-operations was to blame for the blast.
Further investigation into the cause of the accident is underway.