PM10 concentration data for Beijing were combined with trajectory clustering and potential source contribution function (PSCF) methods to identify the principal transport pathways and sources for high-concentration aerosol events in the spring. Three major pathways exist: the main one passes over Kazakhstan, through desert and semi-arid regions in southwestern Mongolia, and then through Inner Mongolia and onwards to Beijing. Four major potential sources were identified, these are: (1) border areas between Kazakhstan and China, (2) desert and semi-desert regions in western Mongolia, (3) the Northern High Dust Desert and (4) the Loess Plateau of China. The pathways and sources for pollution aerosol also are associated with Asian dust emissions; this suggests a significant contribution of Asian dust to PM10 pollution at Beijing.