Zinc oxide, ZnO, is a very interesting compound in science and electronic ceramics technology.ZnO ceramics containing some additives were reported to show varistor action with excellent nonlinearity in current -voltage characteristics.However, investigations were restricted to the ZnO -Bi 2 O 3 ceramic system.Other type of varistor, which contains praseodymium oxide, also present nonlinear behaviour.In this work, results obtained in the synthesis Zn-Pr-Co powder are shown.In order to determine and control the several stages of the chemical method, potentiometric titration was used.The solid phase obtained was pressed and sintered.