Coalbed methane reservoir simulation is the method currently available to determine operating strategies and  estimate ultimate field recovery. Reservoir simulation follows the steps in performing a conventional reservoir simulation study. These steps involve selecting  simulator, establishing simulation model, performing sensitivity analyses, adjusting history matching parameters and forcasting production. Coalbed methane is an  unconventional natural gas. Based on the geology model of desorption-diffusion-Darcy flow，coalbed methane reservoir simulation has its own characters. Systemic  reservoir simulation has been performed in Xinji test area of coalbed methane. The establishment of simulation model and history matching have been emphasized in  the article. Simulating coalbed methane reservoirs is based on the establishment of simulation model, in Xinji test area which consists of determining the area  of simulation and boundary conditions，designing the simulation grid, handling fluid PVT data，reservoir description data and recurrent data and so on. History  matching is the process of calibrating a simulation model to past performance of wells. By history matching a reservoir model that describes the real reservoir  has been created in Xinji test area. Whether the thick sandstone adjacent to No. 5 and 6 coal seam contributes to gas production is analysed. Then suggests aimed  to the behavior of the production wells has been put forward. At last the history match data has been used to predict production rates of wells.