Flow over a circular cylinder is studied numerically using a turbulence model. Based on the κ-ε-f_μ model of Park and Sung[6], a new damping function is used. The efficiency of the strain dependent damping function is addressed for vortex-shedding flows past a circular cylinder. The mean velocity and Reynolds stresses are compared with available experimental data at Re_D= 3900. Also, the computational results for the Strouhal number are evaluated at several Reynolds number. The predictions by κ-ε-f_μ model are in good agreement with the experiments.