The demand for portable oxygen generation systems for patients needing oxygen therapy has been tremendously increased in last decade. Using pressure swing adsorption is one of technologies for oxygen separation from air and producing high purity product. In this process, air flow in a cylinder filled with adsorbent perticles is pressurized. Considering the type of adsorbent and its trend, nitrogen component is adsorbed and after that the outlet product from the cylinder will be air with high purity of oxygen as the final product. The currently available devices for oxygen generation have limited portability due to their size and weight that result in restricted mobility of these patients. A small and light weight device with high purity product can significantly improve the quality of life for those people. The adsoroption columns and the compressor are the two principal factors to the size and weight of the PSA units. On the other hand, continuous producing with no hesitation of desired purity of product is the other key factor that makes these units appropriate for medical applications. The principal focus in this study is designing units with proper size and weight which not only does it generate product with desired purity,but it has portable applicability. Therefore, valveless pressure swing adsorption units have been studied. At first, the dynamic model equations and boundary conditions of the unit were explained for the whole stages. Then by using COMSOL Multiphysics software, simulation of the system for four stages in the cyclic steady state was accomplished. In the simulation we used LiLSX zeolite adsorbent. By completing the simulation of this unit, the effects of various process parameters changes such as bed length, sensitivity to the pressure, bed diameter and pressurization/production time on the process performance were investigated. Afterwards, with the same type of adsorbent and pressure range, highest product purity by changing physical parameters simultaneously was obtained. In the next step, an experimental set-up of this unit was installed on a predesigned preliminary system and all of its parameters including storage tank, type of adsorbent, pressure range and flow rate controllers were adjusted. The importence of adjusting flow rate controllers at every part of the unit is in a way that any little changes in the flow rate controllers can influence directly on the outlet product purity of the storage tank. After completing system adjustments, tempreture changes at the beginig and end of the bed, pressure changes at the beginning and end of the bed, and product purity, which is the most important case, were measured. Experimental results showed a good agreement with the simulation results. Keywords: Portable, pressure swing adsorption, oxygen, continuous producing, valveless, LiLSX zeolite