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An analysis is made of 90 major accidents occurred from 1979 to 1997 in Datong coal mines of Shanxi Province,and it is found that gas accidents occur most frequently(33% of total accidents) and result in heavy damages.The correlation between meteorological factors(temperature,air pressure)and gas concentrations is studied through statistical calculation on a 10-day base.The gas concentration prediction model and the day-to-day graded gas concentration prediction model are established,and the trial application indicates that the models can be used to predict well the tendency of gas concentration in coal mines,so to serve the safety management of coal mine production.