We have investigated transport properties of a cubic Kondo system, Ce0.5La0.5B6, with a Γ8 ground state. The resistivity shows a non-Fermi liquid behaviour in phase I. In antiferromagnetic phase III, the resistivity follows well the formula ρ(T) = ρ(0) + AT2. The coefficient A for phase III is much larger than that of CeB6 in phase III. The magnetic phase diagram for H ∥  has been obtained.