In this investigation, XPS and SEM were used to indicate the changes in surface properties of bitumi-nous coal during natural weathering processes. Natural weathering processes of bituminous coal wereconducted on the roof. XPS results showed that the content of C C and C H groups on bituminous coalsurface decreased but the content of C O, C O, and O C O groups increased after natural weatheringprocesses. Meanwhile, the contents of Al and Si elements on bituminous coal surface were also increased.SEM results showed that the surface roughness of bituminous coal was increased after natural weatheringprocesses. Natural weathering processes not only changed surface chemical composition of bituminouscoal but also changed surface topography of bituminous coal. In addition, natural weathering processesmade bituminous coal surface more hydrophilic.