Adsorbed natural gas (ANG) by Granular Activated Carbon (GAC) has been widely investigated as an alternative to CNG and LNG technologies for storage and transportation of natural gas. In the present work, a theoretical and experimental study was conducted to accurately determine the amount of adsorption of CH4 by GAC. To carry out the experiments, the volumetric method was used up to 4 MPa at constant temperature of 298 K. Also, various adsorption isotherm models were used to model the experimental data collected from the experiments. The accuracy of the results obtained from the adsorption isotherm models was compared and the values for the regressed parameters were reported. The results shows that the amount of CH4 adsorbed is dependent on the physical characteristics of activated carbons. Moreover, the Toth, two term TVFM and Sips isotherm models show good agreement with the experimental data