In order to valuate the effect of air pollution countermeasures on visibility , based on the 15 year monitor data in chongqing,this paper analyses the variation trend of visibility. And the inter relationship among visibility , meteorological factors and air quality factors was also discussed by means of bivariate correlation and partial correlation. The results showed that the seasonal and annual variation of visibility is very obvious. The variation trend of visibility was first down and then up since 1980's.Wind speed can increase visibility by accelerating the transportation and dilution of pollutants and vapour; however, the increase of relative humidity, precipitation , TSP,NO X and SO 2 decrease the visibility.