The molecular cluster model within MNDO quantum chemical calculation scheme was applied to investigate atomic fluorine adsorbtion processes on single-walled carbon nanotubes surface [1]. We were studied adsorbtion properties of two structure modification of carbon nanotube: (n, n) and (n, 0), where n = 6, 8. Boundary binds of nanotube cluster were completed by hydrogen atoms. By means of sequentially (step-by-step) approaching of fluorine to middle part of cluster the 1D-surface of potential energy of its interaction was calculated. Thus the atom F had two degrees of freedom, that is could freely deviate a perpendicular in two mutually orthogonal directions. During calculation the surface center C also had degrees of freedom connected to a possibility of its output from tube surface. As results we obtained that, as rule, the potential energy curves have two minimums corresponding (on our view) chemical and Van-der-Waals’s bonding. The sequentially connecting of F atoms to C atoms of tubes was allowed to find out the fact that the F/C concentration ratio for small diameter nanotubes is 1 until (6, 6) tube. The ratio is decreasing with the diameter increasing: it is already equal to ¾ for (8,8) nanotube. The analysis of the geometrical characters of investigated systems has revealed, that characteristic distance of physical adsorb Rw = 2.5 Å and 3.0 Å, characteristic distance of chemical adsorb Rch = 1.8 Å and 1.8 Å for (6,6) and (8,8) accordingly. In each case the atom F, interacting with a tube surface, attracts to itself the surface atom C. Thus the last leaves a tube surface so that the bond length C-C is increased on the average by 4 per cent in comparison with the case of "pure" tube.