<p>In this paper the author first built and solved a new seepage model for transient pressure analysis of gas wells in triple medium gas reservoirs with a local discontinuous zone by a semi-analytical method. The results obtained by the semi-analytical method proposed in this paper were compared with those obtained by Boundary Elementary method. The factors which affect the pressure transient behavior were analyzed. If the circular discontinuous zone is impermeable and the well located external to the circular discontinuous zone, a “salient” and two “concaves” on the derivative curve will arise during the radial flow period. The “salient” is the reflection of the internal circular impermeable discontinuous zone, and the two “concaves” are the reflections of crossflow between the matrix system or vug system and the fracture system. The longer the shortest distance between the internal circular impermeable discontinuous zone and the well, the later the “salient” on the derivative curve arises and the lower the top of the “salient” is. The bigger the radius of the internal circular impermeable discontinuous zone, the wider the span of the “salient” on the derivative curve will be and the higher the top of the “salient” will be. The model proposed in this paper reveals the complicated seepage law in triple medium gas reservoirs with an internal circular discontinuous zone and contributes a new model to the model library for well testing. It makes us be able to complete well test interpretation for this type of complicated gas reservoir and obtain some important parameters such as elastic storativity ratio of any kind medium, permeability, crossflow coefficient, etc. Besides, it also makes us be able to identify the existence of an internal impermeable zone, the size of it, and the distance from a well to an internal impermeable zone. The model proposed in this paper is most important that it is built and solved firstly by semi-analytical method and the solution is very fit for numerical calculation of computer.</p>