According to statistics from the association, about 90 major domestic coal companies had a total deficit of 13.1 billion yuan ($2.11 billion) in the first two months.

During the same period last year, these companies had realized profit of 11.2 billion yuan.

"China's coal industry is facing more difficulties this year," Jiang said.

During the first quarter, China produced 850 million tons of coal, a 3.5 percent decline compared with the same period last year, according to the association.

Although coal output and imports declined in the first quarter, China's coal inventory is still relatively high. Official data show that the national coal inventory has been above 300 million tons for 39 months in a row.

"Overcapacity has also added to the difficulties for the coal industry," Jiang said.

"China's national coal production capacity is more than 4 billion tons and another 1 billion capacity is being built.

"Meanwhile, consumption of clean energy and other substitute for coal is increasing, which also leads to less coal use."

He said the glut in China's coal industry will remain for a long time, which means companies still have huge pressure for staying profitable.

"The export market is not rosy, either. The international coal market is saddled with excessive supplies for the moment," he said.