Xiaoyangshan Isle, approximately 30 km southeast coast of Shanghai, is surrounded by East China sea. The study of atmospheric aerosol optical characteristics over this region is important for understanding the effect on environment and climate in East Coast of China and its offing. The observation and analysis of the aerosol optical depth (AOD) data for isle near the coast are few in China untill now. The authors used the observed data from 2006 to 2007 to analyze the characteristics of AOD, such as its seasonal variation, the correlation of AOD with surface winds, relative humidity and visibility, etc, and the spectral distributions of AOD are given. The results show that the AOD over Xiaoyangshan isle is the largest in spring, less in winter, and the smallest in autumn. The aerosol is composed of larger particles in low visibility and more larger particles appear in west wind. The AOD and relative humidity have a positive correlation.