The structure, magnetization and electrical resistance for the La 2−x Sr x MnRuO 6 system with double-perovskite structure were investigated. The structural transition from an orthorhombic cell with a random arrangement of Mn and Ru to a cubic cell (rock salt sublattice) with an ordered arrangement occurs at near x=1.0. All samples La 2−x Sr x MnRuO 6 (0≤x≤2.0) show semiconducting behavior. The conductivity for the samples with x≤0.3 at higher temperature has a 2-dimensional variable-range-hopping (VRH) mechanism. But the temperature dependence of resistance for La 2−x Sr x MnRuO 6 (1.0≤x≤2.0) samples can be described using neither a VRH mechanism nor a thermal activation mechanism in a single energy gap. The samples with x<1.0 show ferromagnetism at lower temperatures. The La 2−x Sr x MnRuO 6 (1.0≤x≤2.0) samples show ferrimagnetism below 300 K. The molecular field constant radio N AB /N AA changes with the doping concentration of Sr for La.