Abstract:In this paper, characteristics of air pollution during winter and summer seasons of 2014 and 2015 were analyzed by using the air quality data and the ground surface observation data of Shanghai, and pollution transport paths were analyzed by cluster analysis method and backward trajectory model as well. The results show that the air quality in Shanghai was good and primary pollutants were PM2.5 and O3 respectively in winter and summer. The northwest transport path corresponding to the highest PM2.5 and O3 concentrations, were 62.8 and 130.2 μg·m-3 respectively, and northwest and southwest transport paths corresponding to higher PM2.5 in winter. Then, the transport index was established by combination of potential source contribution function and pollution sources emission intensity and other factors. In general, the pollutants of southern and middle Jiangsu, northern and middle Zhejiang and southern and middle Anhui had great contribution to the quality of Shanghai in summer, while the transport index areas were expanded in winter, including southern Hebei, eastern and middle Henan, Shandong, Anhui, eastern and middle Hubei, Jiangsu and northern and middle Zhejiang.