The characteristics of FY1D meteorological satellite are briefly int roduced. Based on the typical case of FY1D data, the spectral characteristics of fog in the different channels of FY1D are analyzed by using the histogram a nalysis method. The results indicate that the channel 1 and 4 are the represent ative channels of FY1D for the identification of fog. In the channel 1, fog is with uniform texture, smooth top, and clearcut boundary, and its albedo is ab out 20%～48%. In the channel 4, the brightness temperature of fog is 272～289K, and the difference value between the fog and the ground surface is no more than 6K.