A detailed comparison was done between the data about the F in coals pub- lished at home and abroad,and associated with the special situation in China.An intro- duction also was made to illuminate the forming,occurrence and accumulation of the F in coals and its potential hazard to human and environment.Analytical data of coal samples were referred to study the great difference of the F content between coals and gangue. The results show that the average value of the F in the coal samples collected in different coalfields of China is 304×10^(-6),while that of gangue samples is surprisingly 1 319×10^(-6), especially the F content of coal ash from Bangmai in Yunnan Province reaches 4 800×10^(-6). It has been proved in many provinces of China that burning the coal and clay mixture can produce F contamination.