An experimental and computational study is carried out to investigate the flow characteristics around a hydrofoil when free surface presents. In the experimental study a NACA 0012 section is towed in a 2-D flume to document the wave profiles and surface pressure distribution. In the computational study a finite-difference scheme is employed to solve the Wavier-Stokes equations and free surface profiles are obtained directly from the kinematic boundary condition. The calculated results are compared with those of the present and other two experiments to confirm the capability of the present method in free surface problems. The agreement between calculation and measurement is very good. It is found that the pressure on the upper(suction) side of the fail does not drop as much as in deeply submerged case and the lift deceases as a result.