The impact of transport pathways on aerosol properties at Shangdianzi (SDZ) background station was analyzed using the back trajectory analysis method with the observation of PM2.5 concentration and aerosol scattering coefficients ( σ(sp)) during 2005-2010. The results showed that the pollutant level at SDZ was influenced by both the direction and motion state of air masses. The southerly transport pathways of air masses had higher PM2.5 concentration and σ(sp) than those of northerly pathways. The air masses with lower moving speed and altitude generally corresponded to higher PM2.5 concentration and σ(sp). Air masses originated from the North China Plain in spring, summer and autumn, and air masses from the north of North China region in winter had a significant contribution to PM2.5 concentration and σ (sp) at SDZ. Dust aerosol appeared frequently in spring, and the mean scattering efficiency (α(sp)) was 0.78 m2 x g(-1). The mean α(sp) of anthropogenic aerosol of four seasons was 4.00 m2 x g(-1) with the highest value in winter and the lowest in spring. The west-northwest, southerly pathways, and the northerly pathways with low moving speed in spring, summer and autumn correspond to higher α(sp) ( > 4.0 m2 x g(-1)). This indicated that these pathways were affected by the emissions form human activities. However, the α(sp) in winter kept at a high level among all pathways, which suggested that the emission effect was relatively uniform in surrounding regions in winter. The other northerly pathways in spring, summer and autumn were affected by anthropogenic pollutants mixed with dust.