Abstract. The paper presents the results of investigation of the chemical bond formation in fluorinated single-walled carbon nanotubes using X-ray absorption spectroscopy. All measurements were performed with the use of synchrotron radiation at the BESSY II. The C1s and F1s absorption spectra point to formation of covalent chemical bonding between the fluorine and carbon atoms in F-SWCNTs. The investigation of the local structure of the F-SWCNTs has been done on the basis of calculations by the Density Function Theory and Finite Difference methods.