ZnO varistors have an excellent non-linearity and a large surge-energy absorption capability. For these reasons, the ZnO varistors are widely used to protect electrical/electronic circuits from an abnormal surge and/or noise signal. In order to obtain the low-voltage varistor with randomly distributed large seed grain within bulk, the ZnO varistors are made by a new three-composition seed grain method. From the I-V characteristics of the fabricated varistors, the knee voltage of varistors with the seed grain 5wt% is 5 V. We may also present a carrier oscillation properties for the low-voltage varistor fabricated by the new method of three-composition seed grain.