Abstract: Two mathematical models are developed in this paper that describe fluid flow and pressure behavior in a porous medium reservoir and double porous media reservoir consisting of two permeable zones separated by a zone of low permeability, or a "tight zone".Their solutions are obtained which are the exact solutions and the long time asymptotic solutions in infinite formation.The solutions are used to design and to interpret buildup curves,vertical interference tests and vertical pules tests of oil field in a single well or multiple wells for the porous medium and the double porous media.