The microstructure, electrical properties, and its stability of (Pr, Co, Cr, La)-doped ZnO varistors were investigated at different sintering temperatures in the range of $1230{sim}1300^{circ}C$. As the sintering temperature increased, the sintered density increased from 5.50 to $5.77g/cm^3$, the varistor voltage decreased from 777.9 to 108.0 V/mm, the nonlinear coefficient decreased from 77.0 to 7.1, and the leakage current increased from $0.4{mu}A;to;50.6{mu}A$. On the other hand, the donor concentration increased from $0.90{ imes}10^{18};to;2.59{ imes}10^{18}/cm^3$ and the barrier height decreased from 1.89 to 0.69 eV with increasing temperature. The stability of nonlinear electrical properties was obtained from sintering temperature of $1260^{circ}C$. The varistors sintered at $1260^{circ}C$ marked the high electrical stability, with $%{Delta}V_{1mA}=+1.9%,;%{Delta}a=10.6%,;and;%{Delta}I_L=+20%$ for DC accelerated aging stress state of $0.95V_{1mA}/150^{circ}C/24h$.