Effect of Li+ and Mn2+ doping on the electrical properties of SrTiO3-based varistor ceramics was investigated. The results showed that the varistor ceramics cannot possess ideal electrical properties when only Li+ or Mn2+ was doped. However, when Li+ and Mn2+ were properly doped together, the samples acquired excellent electrical properties: V1mA = (5.7 ~ 11.7)V/mm; α = 6.8 ~ 11.0; er = (2.4 ~ 4.4) × 105; tan d = (7.1 ~ 10.4)%. When the contents of Li2CO3 and MnCO3 were 1.00 mol% and 0.05 mol% respectively, the nonlinear coefficient α reached the largest value of 11.0. Compared with only Mn2+ doping, the addition of Li+ increases the α value significantly.