[en] The energy dependence of a conversion length of gamma quanta in liquid xenon in the 25-2400 MeV range is determined by the photos of 180 litre xenon bubble chamber exposed on 3.2 GeV/c π^--meson beams and 0.85 GeV/c K⁺ mesons. The results obtained have been compared with the calculation results. The calculations are performed for xenon which contains a small amount of propane impurity. The conversion length is determined by total cross sections of gamma quanta interaction with Xe, C and H atoms. The xenon main contribution into the total cross section value is given by the processes of electron-positron pairs production and of compton scattering. On the basis of data obtained on the conversion length in liquid xenon with a small amount of propane impurity the cross section of electron-positron pairs production in pure xenon is calculated