Abstract: In the design of micro positioning stage, a motion guiding mechanism is introduced based on bridge-type mechanism in order to take full advantage of large amplification of bridge type mechanism and achieve a high positioning accuracy at the same time, and an improved micro-positioning stage is designed. The displacement amplification ratio and natural frequency formulas of the stage are derived based on theory of materials and Castigliano's theorem. Then the displacement amplification and natural frequency of the stage are simulated by the finite element method, and the results are compared with that computed by the theoretical model. Finally, the micro-positioning system is set up to test the proposed stage. The experimental results demonstrate that the proposed stage has a displacement amplification ratio of 6.4 and a natural frequency of 345.0 Hz. The relative errors of the amplification ratio and the natural frequency between the theoretical model and the finite element simulation are 2.9% and 3.6%, respectively. The relative errors of the amplification ratio and the natural frequency between the theoretical model and experimental tests are 6.7% and 6.8%, respectively. The test results verify the correctness of the theoretical model.