The present invention relates to an apparatus and process of oxygen concentration system to make it possible to produce a highly purified concentrated oxygen,with modifying the structure of the adsorption bed and it achieves evenness of the first and second upper portions and controls to make simultaneous evenness of the first and second upper/lower portions together and thus increases purity of the oxygen produced and reduces mechanical energy and consumption of electricity of the air compressor, then it is about the oxygen concentration apparatus to make it possible to promote pure oxygen enrichment and its recovery rate and the oxygen concentration method to use it.