The determined results of the sulfur contents and isotopic composition of coal samples from major coal mines in 15 provinces and regions of China show that the coal mined in the north of China is characterized by higher34S and lower sulfur content, but that in the south of China has lower34S and higher sulfur content. During the coal-burning process in both industrial and daily use of coal as fuel the released sulfur dioxide is always enriched in lighter sulfur isotope relative to the corresponding coal; the particles are always enriched in heavier sulfur isotope. The discussion on the environmental geochemical significance of the above-mentioned results also has been made.