Aerosol Optical Depth (AOD) in the Zhengzhou area is retrieved according to the BouguerLamber law with the measured data from CE318 photometers in 2008. The monthly and daily variations of AOD in the Zhengzhou area are analyzed, and the effect of whether condition on AOD is studied. The results reveal: In 2008, AOD in the Zhengzhou area was at the same level with that in 2007, but the wavelength index increased. There were evident seasonal characteristics in AOD, higher in spring and summer and lower in autumn and winter, with the lowest value in December. AOD in the Zhengzhou area was mainly affected by industrial dusts. The daily variation pattern of AOD on workdays was different from that on nonworkdays, with the biggest differences occurred in the morning and noon. Traffic contributed most to the differences. Thin fog and haze made AOD increase obviously, and the effect of thin fog on AOD was higher than that of haze. During the sandy/dusty weather process, AOD increased rapidly at first, then descended gradually, and returned to normal level, with a decreased aerosol wavelength index.