Effects of inflow turbulence on the flow around a circular cylinder have been studied using Large eddy simulation( LES) at Reynolds number of 1.4×105.Results show that increased turbulence makes the free shear inter-layer interactions more intense,led to the flow's three-dimensional characteristics more intense.Moreover,turbulence reduces the energy dissipation,strengthens mutual transmission of wake turbulence energy,and thus prolongs the length of recirculation region.With increasing length of the recirculation,mean base pressure coefficients increased,resulting in the mean drag coefficient decreases.As the wake turbulence is enhanced the wake region will form enhanced multi-scale turbulent,which leads to appearing multiple frequencies in the power spectrum density of the wake flow.