ZnO particles were synthesized via fast crystallization of precipitation technique by dissolving zinc and iodine in ethanol. The synthesized ZnO particles are pure and exhibits hexagonal wurtzite structure with the preferred orientation growth in (101) plane. The crystallite size is about 50 nm whereas FE-SEM images shows nearly spherical shape with the grain size of approximately 0.6 µm. The shape and size of the particles have a great influence on the impedance spectroscopy; therefore it is directly related to the conductivity of ZnO particles. The complex impedance of the MSM ZnO thick film shows two distinguished semicircles in which these arcs show a decrease in its diameter as the bias voltage increases from 0 to 5 V. The modeling of the MSM reveals that the bias voltage affects mainly the grain boundary components with the grain boundary resistance decreasing from approximately 207 M to 40 M, while the grain boundary capacitance increases from 5.14 pF to 43 pF as the bias voltage increases from 0 to 5 V.