Lately a dynamic increase of piezoelectrical materials applications can be noticed in many fields of industry. The materials refering to the intelligent materials are widely applied as sensors and actuators. Such materials show simple piezoelectrical phenomenon that consists of changing mechanical displacement into electrical voltage input signal, as well as opposite piezoelectrical phenomenon that generates mechanical displacement when voltage is applied to system plates. Advantages such as: little dimensions, simple structure, low noise factor at operating provide wide applications generating and damping in vibration, converse of mechanical energy into electrical energy and opposite, elements of precise positioning and many others. In this article the analysis of piezoelectricity phenomenon is presented on the grounds of Mason's equations. Matrix of dependency of input values on output values has been determined. In most cases the system considering merely external parameters is sufficient. Thus the system is limited to a few single four-terminal networks. There has been established the matrix determining the system from external terminals point of view. Then by the chain joint the matrix of input-output dependences is provided (Bolkowski, 1986). Further proposed studies and research are to determine characteristics of mechatronic system and its comparison to the characteristic of mechanical system solved by Galerkin's method of approximation. The opportunity of applying graph method Buchacz, Wrobel, 2006) to non-classical determination of flexibility of piezoelectrical plates will be also analyzed (Buchacz, Swider, 2000; Buchacz, 1997).