Abstract: The Lorentz forces generated by electromagnetic fields on the surface of the cylin-der in the electrolyte solution may modify the structures of the flow boundary layer effectively.In this paper,control of vortex-induced vibration by Lorentz force is investigated experimentally which aims for vibration suppression.Experiments are conducted in a rotating annular tank filled with a low-conducting electrolyte.A long metal sheet was used as a flexible support to mount the cylinder with a 2cm diameter.The cylinder with an electro-magnetic actuator mounted on the surface is placed into the electrolyte.Force measurements have been carried out by strain gages attached to a fixed beam to which the cylinder is suspended and flow fields are visualized by dye markers.The results show that since the upper vortex and lower vortex are shed at upper and lower maximum displacement related to the cylinder,the vortex street formed is composed of two parallel rows with an opposite signs of the vortices.With the application of symmetrical Lorentz force the vortexes of cylinder are suppressed which leads to the suppression of lift oscilla-tory and then the vibration of cylinder is suppressed.The vortex street formed is composed of two parallel rows which turn to the composition of negative and positive staggered vortices. When the Lorentz force is large enough,the flow on the surface of the cylinder is accelerated by the Lorentz force which causes the flow separation point to move downstream and disappear grad-ually.Then,the vortexes move downstream away from the cylinder and the vibration amplitude of cylinder begins to decrease.The vortex shedding is suppressed fully and the vibration is decay-ed rapidly.Finally,the vibration is suppressed fully so that the flow field is steady.