Beijing suffers from severe atmospheric pollution since decades. The sources of aerosols in Beijing are manifold. On the one hand anthropogenic dust sources are polluting the atmosphere of this megacity, on the other hand Beijing has to cope with strong dust storms originating in the deserts of Gobi and Takla Makan. Any future sustainable urban planning needs urgently the comprehensive understanding of processes of aerosol production, distribution, transformation processes, deposition and composition. The main emission sources shall be investigated for their elemental and mineralogical composition in an interdisciplinary and international approach (5 different research groups of China and Germany). A fingerprinting system will be established. Aerosols shall representatively be collected and analysed for the mineralogical and elemental contents in the urban area in a manner that reflects typical land use types (emission source combinations) and the impact of natural sources due to long range transport from the deserts and due to short range transport, e.g. from bare soils or coal heaps. Carbon plays a specific role, since it occurs in several distinct phases such as soot, biological components, organic carbon or carbonates that contributes to the identification of emission sources. Thus, the spatial distribution of aerosol geochemistry will be analysed and emission sources identified as basis for simulation modelling resulting in effective mitigation measures. Furthermore, bio-availability and chemical speciation of elements in aerosols shall be investigated with regard to an environmental assessment of possible toxic effects and further chemical reactions effecting particulate matter.