In the given work the results of investigation of hydrogen interaction with multiwall conic carbon nanotubes (CNT) during their electrolytic hydrogenation in a water solution of a sulphuric acid are presented. Hydrogen sorption by carbon nanotubes was studied by (1)H nuclear magnetic resonance (NMR) spectroscopy. It has been found, that hydrogen chemisorption at dangling bonds of "bamboo"-type and "fish bone"-type carbon nanotubes from hydrocarbonic plasma occurs directly during their growth. The significant narrowing of the (1)H NMR linewidth in the process of annealing and electrochemical hydrogenation of carbon nanotubes is revealed. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.