ZnO low voltage varistor was obtained by varying a) the amount of seed grains, b) the size of seed grains, and c) sintering temperature. Also, the optimum condition for fabricating the ZnO seed grains was studied. Large ZnO seed grains were obtained by washing a ZnO sintered body containing 1m/of BaCO3 in boiling water. When the seed grains were added, abnormal grain growth occurred, and the varistor voltage sharply decreased. However, when more than 5w/o of seed grain content was added, the varistor voltage gradually increased. When 10w/o seed grains of 75~106${mu}{ extrm}{m}$ were added and sintered for 2 hours at 1200 to 125$0^{circ}C$, low voltage varistor properties with V1mA/mm of 19V/mm and nonlinear exponent ($alpha$) of 12 occurred.