Abstract: Based on the relationship between the exciting current, axial position of giant magnetostrictive material and magnetic field intensity, which was obtained from the experiment of giant magnetostrictive actuator(GMA), the theoretical formula between the current along the axis of the coil around the thick-wall hollow column and magnetic field intensity was corrected. With the corrected formula used, the dynamical model of GMA was analyzed theoretically to get the vibration responses of GMA. Then, the effects of correction factors, bias magnetic field and pre-compression stress on GMA were discussed. The results indicated that the correction factors affect the dynamical characteristics of GMA greatly, e.g., if the correction factor K′=1.24, the hysteresis loops between output displacement and input exciting current that obtained by the experimental fitting function and the theoretical formula as above match perfectly. The vibration responses of GMA have distinct nonlinear characteristics and they are affected greatly by correction factors. Meanwhile, the bias magnetic field and pre-compression stress have distinct influence on amplitude-frequency characteristics of GMA.