In order to evaluate the development prospects of coalbed methane (CBM) of Long flame coal reservoirs, we analyzed the coal maceral, equilibrium moisture content, industry analysis and physical characteristics of 34 long flame coal samples (testing 18/collecting 16) nationwide. Moreover, Isothermal adsorption experiments and the calculation of coal surface energy were carried out. The results show that: equilibrium moisture, dry ash-free volatile and air-dried basis moisture of long flame coal decrease with increasing degree of coalification, but porosity increases with increasing degree of coalification. And the pore volume is unevenly distributed, the macropore accounts for most of the total volume (about 40%), the specific surface area of transition pore and micro pore has an absolute advantage (about 97%). Langmuir volume shows an increasing trend with increasing inertinite content, and shows an decreasing trend with increasing vitrinite content. Besides , both Δγ_L and Langmuir volume increases with the increase of degree of coalification, and decreases with increasing temperature, so it is obvious that coal surface energy controls the action of methane adsorption. Nationwide, The CBM resources of long flame coal within the 2000m were estimated at 4.3×10¹² m³.The porosity of long flame coal is larger, pore connectivity is better, and pore size distribution is continuous. Thus, the CBM resources of long flame coal has the development potential. At present, the low rank CBM development in our country has not yet achieved a breakthrough in the scale of commercial development. In this paper, we provided a basis for the study of long flame coal reservoir for low rank CBM development, pointed out its physical characteristics and advantages, and combed CBM resources of long flame coal located in different regions, which has certain guiding significance for CBM development of long flame coal in the low rank coal.