In this paper, in order to understand the flow-pipe interaction more clearly, the variations on flow pattern around semi-buried pipelines due to steady current have physically and numerically been investigated. In physical modeling section, the experiments have been carried out in a flume with 10 meter length, 0.3 meter width and 0.5 meter depth using a P.V.C pipe with 6.35 cm in diameter (for different burial depth-diameter ratios). To visualize the flow patterns, the polystyrene particles with 0.4 mm in diameter and 1.05gr/cm3 in density have been used. In order to understand the phenomenon as well as possible, the whole processes of tests have been recorded using a digital camera. For the numerical simulation section, the flow field has been analyzed using a computational fluid dynamics software “FLUENT”. For the software, the governing equations are descretized using the finite volume method. Geometry and mesh production have been done using a pre-processor software called “GAMBIT”.