This paper reports on design, fabrication and experimental testing of one port ZnO piezoelectric contour- mode MEMS resonator. This is a rectangular plate formed by ZnO layer between two electrodes platinum and aluminium. A vertical electric field is applied to a layer of ZnO and induces in plane dilation of the plate through the d31 piezoelectric coefficient. In this paper we will look at the rectangular plate vibrating in the length-extensional mode and the width-extensional mode. The frequency equations of the length-extension mode and the width-extensional mode are calculated. The equivalent Butterworth Van-Dyke circuit of resonant microstructure is presented. The equivalent parameters of the resonator for the length-extensional mode are expressed and the fs series and fp parallel resonant frequencies are calculated. The method of fabrication of the resonator ZnO is presented. The ZnO layer was deposited using radio frequency magnetron sputtering. The XRD pattern of ZnO is presented. The SEM of contour-mode ZnO 10x5.6 Μm resonator is presented. The electrical characterization of the resonator system was carried out using the S11 scattering parameter measured with a Suss Microtech prober coupled with a Hewlett Packard 8753 Vector Network Analyzer. Key experimentally determined parameters for the contour mode ZnO MEMS resonators are presented. Measured S11 is plotted. Parameters of the ZnO and the AlN contour-mode resonators are compared. The use of contour modes, whose frequencies are set by lithographically defined dimensions, permits the fabrication of multiple filters at arbitrary frequencies on the same chip.