The ionic conduction in polycrystalline Li3+xV1-xTxO4(T=Si, Ge) has been studied by using AC impedance method. It was found that some processing conditions, such as forming pressure, sintering time and sintering procedure have great effect on ionic conductivity. The attention was focused on the physical origins of these effects. The best specimens could be prepared under forming pressure about 8t/cm2 and continual sintering at 1000℃ for 5 to 6 days. The temperature fluctuation should be avoided during sintering process. We found that, at 25℃, the bulk ionic conductivities of polycrystalline Li3.5V0.5Ge0.5O4 and Li3.3V0.7Si0.3O4 prepared under optimal conditions are 2.2×10-5Ω-1cm-1and 1.9×10-5Ω-1cm-1 respectively.