The methods of functionalization of carbon nanotubes and thermally exfoliated graphite by inorganic and organic compounds, which allow obtaining of oxygen-containing groups on the nanocarbon surface were proposed. The influence of chemical treatment on the internal structure and surface morphology of nanocarbon is analyzed. The electron microscopy, Raman spectroscopy, and IR spectroscopy methods were used for investigating the structure and qualitative composition of functional groups on the chemically treated nanocarbons surface. The presented data reveal some modification of the typical nanocarbon Raman bands such as disorder band (D band), the graphite band (G band). But the changes of nanocarbon structure under chemical treatment are not dramatic.