Abstarct: If condition change during a steady state to another steady state, the unsteady flow occurs between two steady flow that between flow the call transient state flow so, water hammer is a kind of transient state flow that in the pipeline is created. This creates considerable dynamic forces to pipeline’s structure. If these forces can cause movement of the pipe network phenomenon called fluid structure interaction will occur. This phenomenon involves transmission of energy and momentum between the pipeline’s structure and the fluid and is normally produced by intensive change of flow rate and fluid pressure or mechanical factors in pipeline systems. This phenomenon pioneered by Skalak, examined. For this purpose, he used the governing interaction equations water hammer. As the governing equation are hyperbolic in this phenomenon, For analyzing and simulating this interactional feature, In the past, for analyzing and simulating this interactional the method of characteristics (MOC) was used. But due to some reasons like encountering with nonlinear equation systems or existence of complex terms in model using MOC method has some limitations. There for, in this study, for modeling Godunov numerical method, have been used. The scheme is baxsed on Reimann solution and The implementation of boundary conditions such as reservoirs, valves and pipe junctions within the Godunov approach is similar to that of the method of characteristics. In this modelling, considering the unsteady friction models. In the end, for evaluating model results, developed model compared with the existing lab tests and analytical results presented by pervious researchers. Obtained results indicate that Godunov method in the field of analyzing hyperbolic system of equations is stable for Courant number less than or equal to one and efficient and can be used.