Abstract: A great amount of low concentration coal bed methane are released during coal mining，and it is important for energy utilization and environmental protection to make good use of this resource. The challenge of the recovery of low concentration coal bed methane is to separate nitrogen and methane economically. In this paper，several kinds of CH4/N2 separation technologies are introduced，and their application prospect in coal bed methane concentration is discussed. Researches on different adsorbents in pressure swing adsorption (PSA) process for nitrogen and methane separation are reviewed as well as their advantages and disadvantages in coal bed methane concentration. Preparation of carbon molecular sieves (CMS) is also presented to make the CMS more suitable for coal bed methane concentration.