The existing forms of Fe are of great interest since they have a profound effect on the biological availability of Fe. In this work, aerosol samples collected in different seasons and at different locations in the Qingdao region were examined by means of extended X-ray absorption fine structure (EXAFS) K-edge analysis of Fe, X-ray diffraction (XRD) and Fe content analysis. The results showed that an iron ion in aerosol particles is surrounded on average by 5.8 (coordinated) O ions. For the six samples examined, the coordination number of the first Fe-O coordination subshell is always 3 with a coordination distance (with O) in the range of 1.952similar to1.966+/-0.002 Angstrom, while the coordination number of the second subshell varies from 2.2 to 3.0 with a coordination distance of 2.108+/-0.002 Angstrom. The coordination is approximately consistent with that of alpha-Fe2O3, suggesting that iron in aerosol samples is mainly present in the form of alpha-Fe2O3. The fact that the coordination number in the second subshell is smaller than that of alpha-Fe2O3 might be an indication that there is a small amount of FeO mixed with alpha-Fe2O3 in aerosol particles. Existence of FeO is confirmed by a later XRD experiment.