Using the data of visibility and vapor pressure measured in Nanjing, Hangzhou, and Hefei from 1961 to 2001, the 055 μm aerosol optical depths (AOD) of these areas are inverted, and the variation characteristics of visibility and AOD are analyzed. In addition, the variation characteristics of solar radiation from routine radiation measurements are analyzed and compared with the variation characteristics of AOD. The results shows that the visibility over these three cities had significant decreasing trends from 1961 to 2001; the fastest decrease of visibility appeared in Nanjing and Hangzhou, while the slowest in Hefei. Visibility had also seasonal variation, maximum in summer and minimum in winter. AOD not only showed increasing trends, fastest in Nanjing and slowest in Hefei, but also had seasonality, higher in spring and summer, lower in autumn and winter. The global radiation and direct radiation had a significant decline in all the three cities before 1990, while the diffuse radiation did not change obviously. However, a slight increasing trend of global radiation was found in Nanjing and Hefei after 1990 Seasonal total of radiation is in the following descending order: summer, spring, autumn, and winter. A negative correlation between AOD and direct radiation has been found.