The powders of Li4xTi1-xP2O7 (x D 0, 0.06, 0.1, 0.2) pyrophosphates have been succesfully synthesized by solid state reaction. The powder XRD analysis has proved, that Li4xTi1-xP2O7 (x= 0, 0.06, 0.1, 0.2) crystallize in cubic 3 £ 3 £ 3 superstructure (space group Pa 3). The partial substitution of Ti4+ by Li+ in the Li4xTi1-xP2O7 system leads to the conductivity increase. The deviation from Arrhenius law in total conductivities has been found in the temperature range from 520 to 580 K. The changes of the activation energy can be related to disordering in the supercells of the investigated compounds. The above mentioned titanium to lithium substitution also increased the values of the static dielectric permittivity of TiP2O7 is almost temperature independent, while for Li4xTi1-xP2O7 with x = 0.06, 0.1, 0.2 it is increasing with temperature, this increase is due to the additional lithium migration polarization.