This paper investigates a way to assemble spin transfer torque oscillator and magnetic random access memory together. It would be shown that what radius and which material of ring is most effective in switching onion state, clockwise vortex state and counterclockwise state by injecting perpendicularly to plane polarized current. What fabrication of cylinder of different material inserted in the hole of ring could be suitable to get stable microwave and easily-controllable magnetization state also would be covered in this paper.