Soil organic matter is often stated to contain a highly complex and heterogeneous mixture of organic carbon forms. It also becomes increasingly clear that stabilization mechanisms of carbon in soil occurs on the level of small pores and mineral surfaces. Until recently, it was not possible to study the nano-scale distribution of organic carbon forms in situ. Using near-edge x-ray absorption fine structure (NEXAFS) spectroscopy coupled with scanning transmission x-ray microscopy (STXM) it was possible to image organic carbon forms with a resolution of 50 nm in a two-dimensional view. Carbon contents did not increase in the interior of microaggregates (smaller than 250 microns), but rather hotspots of carbon accumulations could be found which were situated at any position within the microaggregates. Carbon forms differed more on a the scale of a single pore than on the scale of an entire microaggregate. Carbon forms were only slightly more complex within an aggregate than near the surface. In contrast, carbon forms on mineral surfaces within a pore differed greatly from those in pores of micrometer size. Surface coatings were dominated by aliphatic-carboxylic functional groups, whereas organic matter filling pores had greater proportions of aromatic carbon. The nano-scale variations of carbon forms in microaggregates were much greater than those observed between differed soils or soils at different stages of degradation. With this perspective, characterization of average proportions of carbon forms in soil appear rather meaningless for the investigation of carbon cycling processes in soils.