Synoptic and climatic characteristics of dense fog and associated weather conditions in Anhui Province are analyzed. A multi-regression equation is developed on the basis of factors which reflect the weather features in the formation of dense fog through correlation verification by use of 3-years T106 data. An operational forecast system used to forecast 24-72 hours dense fog is eventually confirmed through the verification of one-year T213 data. Forecast results show that the forecast system is helpful for the forecast of dense fog of the stations in Anhui Province.