Abstract: Used the monthly fog data(1961—2008) of 120 stations of Yunnan Province,the change characteristics of spatial and temporal distribution in the nearly 50a and its response to Global Warming were analyzed.The results indicated that ①The Yunnan fog has obviously regional distribution.From north to south,the number of annual and four seasons fog increases.②The Yunnan fog has obvious intermonthly change.There is fog happening in each month and happens mainly in November,December or Juanury.Yunnan Province belongs to typical winter fog region.With a view to the climate belts,north tropic zone,south subtropic zone,middle subtropic zone,north subtropic zone and temperate zone belongs to typical winter fog region.The most fog happens in December.Plateau Climate zone belongs to typical summer fog region.The most fog happens in July.③In nearly 50a,the fog change trend of the whole year and four seasons in Yunnan consistently reduced.The trend of six climate zones also reduced.④There are also obviously interdecadal change trend in the annual and the four seasons fog of Yunnan.There are also obviously interdecadal change trend in the six climate zones.⑤The response to climate warming is inconsistent in Yunnan .The fog of most areas of west,south of Yunnan is very excellent relationship with climate warming.When the climate is warmer,the fog may decrease;and vic versa.