Natural gas is an attractive alternative for conventional fuels due to low price, being naturally abundant and less toxic gas emission. To develope the ANG thechnology, appropriate adsorbents with superior chractarestics and high storage capacities are required for development. Carbonaceous materials due to their appropriate properties have been evaluated for natural gas adsorption. With respect to the unique characteristics of carbon nanotubes, representation of appropriate gas storage properties by ANG method is an interesting projected area. In the first chapter, natural gas adsorption on different types of carbon nanotubes was investigated and compared to the adsorption data obtained by Granular activated carbons. Then, the effects of various chemical treatments on the performance of carbon nanotubes for natural gas adsorption were examined and discussed in the second chapter. Furthermore, sorption equilibria, kinetics and thermodynamic studies of adsorption processes were evaluated in this book.