The effects of amount of purge gas on the Pressure Swing Adsorption (PSA) performance was investigated for hydrogen separation from various feed compositions. Linear driving force (LDF) model was used to describe mass transfer between two phases. Extended Langmuir isotherm was used for each component as a nonlinear adsorption isotherm. In order to consider the influence of temperature, energy balance was set up along with mass balance equation. The results indicated the importance of purge gas in this process. According to amount of purge gas, adsorption efficiency and concentration of hydrogen were changed and finally separation performance on the purity and recovery was influenced.