end section storage is the most economic method of a short-term peak shaving for a gas transmission line. Calculating its storage capacity can be useful to planning, design and operation of a gas pipeline. Based on several reasonable hypotheses, an equation set was established to describe a real isothermal flow of gas in pipeline and solved by mixed TVD scheme. Some parameters such as flow rate and pressure in end section of a gas line was simulated that by programming. According to a case example and calculating results, storage capacity of end section was figured out. Keywords: gas transmission line；peak shaving； storage capacity of end section