Abstract. This paper provides a new design of gold tip optical nano antenna based on a special shape, and then the change of enhancement of the electric field of plane wave laser excitation with visible wavelength range in the around of optical antenna are simulated. Changing the geometrical of optical nano antenna includes of creating circular gratings on the shaft of antenna. With the applying of laser light to these gratings, the maximum enhancement of the electric field in a plane perpendicular to the shaft has been obtained. Finally, the diagrams for the considered geometrical parameters in order to achieve maximum electric field intensity were obtained.