ABSTRACT : The planar microstrip rectangular disk resonators are useful integrated circuit components at microwave and millimeter-wave frequencies for building bandpass and bandstop filters, oscillators (in controlling and stabilizing the frequency), tuned amplifiers, frequency meters, phase equalizers. The definition of a planar circuit is an electrical circuit having two dimensions, which are comparable with the wavelength, and the third dimension is negligible fraction of the wavelength. A review is given of the derivation of two dimensional wave equations and formulation of impedance matrix in terms of the Green's function of the wave equation. Details on the analysis and design of microwave networks comprising one or more planar microstrip rectangular disk resonators are presented. General expressions for the impedance and scattering parameters of multiport single resonators and interconnections of single resonators networks were derived. Different analytical techniques are developed to compute the scattering parameters of networks of more than one resonator which are formed when two port resonators are cascaded or when multiport resonators are interconnected. Using effective dynamic permittivity of the dielectric and effective physical dimensions of the resonators, a number of computer programs have been developed to determine the frequency responses of some typical networks. An optimization for controlling the resonators parameters were also developed using a powerful Visual Basic Program in order to show the results generated by Fortran Program directly on a P.C. screen Curve wise & Table wise.