In this study, ultra high-voltage (170kV AC), reliable 80pF mica capacitors for partial discharge system application were investigated. For capacitors design, Program was developed to sampling of series and parallel parameters. Mica was used as the dielectric of the capacitors. Using the conservative design rule, over 3 individual 50$mu$m thick mica sheets with a size of 30mm$ imes$35mm were used with lead foils to form a parallel capacitor element and 20 mica sheets were interleaved with lead foils to form a series stack of parallel capacitor element to meet the requirements of the capacitors. The dimension of the fabricated 80pF capacitor for 17kV AC were 90mm$ imes$90mm. The high-frequency characteristics of the capacitance (C) and dissipation factor (D) of the developed capacitors were measured using a capacitance meter. The developed capacitor exhibited C of 79.5pF, had D of 0.001% over the frequency ranges of 150kHz to 50MHz, had a self-resonant frequency of 65MHz.