Pyrochlores Mg-, Sc-, Cu-doped bismuth titanates have been obtained. The results of X-ray powder diffraction structure refinement and the pycnometric density measurement point to the preference of the dopants distribution in the A-sites of the pyrochlore structure. Electric properties were studied for single phase compounds. The mixed electron-ionic conductivity was indicated in these samples. The high temperature (T> 300 degrees C) relaxation process was observed in Bi1.6MxTi2O7- (delta) at the range of frequency 10(3)-10(6) Hz. Oxygen mobility and surface reactivity of Bi1.6M0.2Ti2O7- (delta) (M Sc, Mg and Cu) and Bi1.4Mg0.2Ti2O7- (delta) samples were studied by using temperature programmed isotope exchange (TPIE) with (CO2)-O-18 in flow and closed reactors. According to TPIE data the regular lattice oxygen is homogeneous from the point of view of its mobility. (C) 2016 Elsevier B.V. All rights reserved.