For the first 11 months of 2014, the country produced 3.5 billion tons of coal, a 2.1% drop over 2013, reported Xinhua.
Major coal companies reported profits of CNY110.5bn ($18bn).
The agency estimated that the coal production will drop 2.5% for the full year 2014.
CNCA vice-president Jiang Zhimin was quoted by the news agency as saying that the coal industry will continue with oversupply and pressure on the companies in 2015 due to new environmental regulations.
As of 2014, Chinese coal companies had 87 million tons in stock and major power plants had 94.6 million tons.
CNCA analyst Zhang Hong said: "Demand is slowing. Overcapacity is yet to be digested and environmental constraints are constantly in the headlines as we transform the growth mode."
