Influence of the flow induced by dielectric barrier discharge (DBD) plasma actuators on the wing-tip vortex is investigated numerically and experimentally. The plasma actuators are installed on the suction side of the NACA0012 airfoil and operated in blowing and suction modes. For the numerical simulation, direct numerical simulation (DNS) based on the finite-difference immersed-boundary method is used. The DNS shows that the circulation parameter, which measures the strength of wing-tip vortex, is reduced by blowing as well as suction. At the same time, however, the lift-to-drag ratio is found to decrease by the actuation. In the experiment, a wing model with plasma actuators is set inside the wind tunnel and the velocity components are measured using a PIV system. Although suppression of wing-tip vortex is not confirmed due to insufficient strength of actuation and insufficient length of messurement area, the change of streamwise mean velocity profile is found to be similar to that of DNS.