The method of thermodesorption spectroscopy has been used for study of kinetic of hydrogen, oxygen and water molecule release from doped and undoped barium and strontium cerates. It was found that oxygen and water molecules are released from doped barium cerate samples whereas only water molecule desorption took place from doped strontium cerate samples. Shapes of thermodesorption spectra for pure barium cerate indicate that phase transformations take place in low and high temperature regions. It was shown that oxygen molecule desorption from doped barium cerates can be described by a second-order kinetic equation and an activation energies of reaction were determined. (C) 2003 Elsevier B.V. All rights reserved.