The servovalve is essentially a regulating system. The output (flow, pressure) is controlled by the electric control input. There is a negative feedback. This feedback can be mechanical, hydraulic and electrical. The analysis is realized on linearising mathematical models. The paper presents the mathematical model for a SV60 servovalve. The dynamic conduct of a servovalve is described by means of the equations of the constituent elements. In this way it is obtained the block diagram that permits the numerical simulation of the servovalve using the state variable method.