Wide use of phosphates in different areas motivates interest to investigation of these compounds. Knudsen effusion mass spectrometry was used to study thermodynamic properties of gaseous lead phosphates. On the basis of the measured constants of the equilibrium of gas-phase reactions the standard formation enthalpies of PbPO2, PbPO3 and PbP2O6 have been defined. For these gaseous lead phosphates thermodynamic function were calculated by statistical thermodynamic method in "rigid rotor-harmonic oscillator" approximation. The molecular parameters obtained by different quantum chemistry method. (C) 2016 Elsevier Ltd.