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The distribution and the climate characteristics of fog in Shangqiu are analyzed by use of fog data from eight weather stations in Shangqiu from 1961 to 2004. The results indicate that fog days occurred more frequently in the west part such as Suixian and Ningilng than in the south part such as Zhecheng and Xiayi. There was an increasing annual tendency in foggy days and a Vshaped monthly variation feature with the maximum in fall and minimum in summer. The fogs occurred generally in early morning, and dissipated most likely at seven to eight o'clock after sunrise. The duration of fog was mostly less than 3 hours and there was no fog maintaining more than 24 hours. Based on the weather maps from 1999 to 2004, the surface synoptic patterns favorable for foggy days can be classified to four kinds: continental anticyclone, warm zone in front of cold front, uniform pressure field, and low pressure with an inverted trough.