The electromechanical properties of a newly proposed 3-dimensional piezoelectric actuator have been investigated. Especially, the effects of 3-dimensional geometry on the maximum tip displacement were carefully investigated. As a result, it was found that the maximum strain of the 3-dimensional piezoelectric device was significantly enhanced up to 4.5 times higher than that of a disk shape device. This data was in good agreement with the finite element model analysis of strains and vibration modes. Moreover, the field -induced displacement stability of dome-shaped 3- dimensional piezoelectric actuator at various ac freguencies was superior to Rainbow actuator.