The study of flow around circular cylinders is one of the challenges in marine hydrodynamics. Many offshore structures are of cylindrical shape such as spar hull, risers and pipelines. Furthermore, the flow around cylinder open the path for studying more complex shape structures like ellipses, flat plat and other complex geometries. The aim of the study is to understand the flow field around these structures and calculation of forces acting on them. In current study, flow over a circular cylinder is investigated numerically using the turbulent model Large Eddy simulation (LES) and SIMPLE pressure-velocity coupling. In LES option, Smagorinksy-lilly subgrid scale model with dynamic stress is used. Mesh is generated using ICEM CFD tool and analysis is performed using ANSYS fluent. Velocity profiles are investigated in the cylinder wake up to ten diameters and compared with the experimental results. Hydrodynamic values and pressure distribution on the cylinder wall are also analyzed. The numerical results extracted from the simulation agreed well with the experimental results available in the literature. Furthermore, the spanwise mesh resolution study shows that flow around cylinder at Reynold number Re = 3900 is highly 3dimensional study and 2D study or coarse mesh in spanwise direction will deteriorate the results.