Abstract: In this paper, the dynamic performance for a high frequency electro-hydraulic servovalve and its main elements are investigated. A simple and practical method for testing its dynaamic performance is de scribed. The relations between armature magnet saturation and torque moor output are discusseed. Based on experiments and the identification theory, mathematical models for the torque motor and the whole valve are built and programs for aomplex curve fitting are presented. The result shows that the values of frequency characteristic corresponding to the identified model are in good agreement with the experimental data, thereby showing the practical significance of the identification method in hydraulic control systems.