Ground-level ozone(O3) and atmospheric fine particulate matter (PM2.5) pollution are the major challenges for continually improving air quality in the Yangtze River Delta (YRD) region of China (Lu et al., 2020; Wei et al., 2020). Understanding regional transport pattern of PM2.5 and O3 pollution is essential for the development of regional cooperative prevention and control strategies. This study shows annual concentration of PM2.5 in the YRD decreased by 18.5% from 2015 to 2018, while average of daily maximum 8-h average(MDA8) O3 concentration during March to October increased by 16.3%. A complex network method is developed to investigate regional transport of PM2.5 and O3 in different grid cells (nodes). Source apportionment technology in regional transport model is applied for comparing with the results from the complex network method. Interregional and intraregional transportation play an important role in both PM2.5 and O3 over the YRD. The northern part of the YRD contributes much more than other areas for PM2.5 in winter, which accounts for about 60%,while the central part of the YRD, especially the northern part of Zhejiang, is the largest contributor of O3 in the YRD in summer,which accounts for about 70%. Intraregional transport played major role in PM2.5 than O3. The study focusing on heavily pollution episodes not only show results between source apportionment technology and complex network method are comparable, and also reveals both two methods pose great potential in understanding transport pattern and air pollution relationship, which is the foundation for emission mitigation in the YRD region.