Based on the NCEP/NCAR reanalysis data, the features of atmospheric circulation and meteorological factors of the 6-day continuous cloud deck appeared on January 19 to 24, 1984 in Huangshan mountain are analyzed, It shows that the event occurred under the conditions as follow. At 500hPa level, a blocking high laid in Okhotsk, the pressure ridge in Wulaershan leant towards east, a depression laid over Northeast China, and westerly flow over the Huangshan mountain. At 1000hPa, a northeasterly forward high is over the Huangshan Mountain. The cloud deck appeared after cold front and heavy rain, and then temperature and humidity droped, and the upward current turned into downward motion. During the appearance of cloud deck, the temperature, the specific humidity, and the vertical velocity are changing less, and the wind velocity is lower, but the wind direction is chaos.