Zeocarbon was synthesized from rice hulls. The adsorption equilibrium of H₂O on zeocarbon was compared with that of zeolite 13X. The experimental data of H₂O adsorption on zeocarbon and zeolite 13X were fitted by various isotherm models sush as Langmuir-Freundlich, Excess Surface Work(ESW) and Multi-BET model. Specially, ESW model was found to be better agreement with experimental values than Limgmuir-Freundlich model and Multi-BET model. ESW model was applied well at all temperatures and pressure considering mono layer adsorption in low pressure region and capillary condensation phenomenon in high pressure region.