Abstract: By using the historical observations from 1980 to 2010 to research the annual change and monthly change for the fog in Bazhong,with Comprehensive utilization of upper-air data,surface data and NCEP 1×1° reanalysis data,it analyes the causes of fog in Bazhong.According to Bazhong geographical features,elect the meaningful meteorological elements to built the forecasting fog modle by VB application platform software,the result showes that the model can predict the heavy fog in our city well,there is a good reference value.