The adsorption of hydrogen molecules on different zeolites at near room temperature and extremely high pressures has been simulated employing Grand Canonical Monte Carlo (GCMC) method. Some important physical amounts under different temperatures and pressures, such as adsorption isotherms, adsorption amounts, and isosteric heats were studied. We predict the storage capacity of hydrogen in ZON and CHA zeolites at different conditions. The results show that the hydrogen storage capacity of CHA is superior to that of ZON. The different hydrogen adsorption behavior between them is explained by the isosteric heats of adsorption at different temperatures. These results may help us to understand different hydrogen adsorption properties of these two zeolites, thus facilitate exploring new hydrogen storage candidates experimentally.