ABSTRACT The intensities of water vapor in the range of pure rotational transitions were calculated up to high quantum numbers(J max ~ 30 and K amax ~ 25). The diagonalization of the effective rotational Hamiltonian, approximated by Pade-Borelmethod, is applied to obtain the eigenv ectors. The centrifugal dist ortion perturbations in line intensities were taken into account by the traditional equatio ns for matrix elements of the transformed dipole moment, including eight parameters,and previously developed by authors Pade approximant. Moreover, to conduct the calculations, the rotationalwavefunctions of the symmetric rotor molecule were applied. The results were compared with the known theoretical data. Water vapor, high-temperature spectra, centrifugal distortion effects, Pade-Borel approximants, symmetric rotors 1. INTRODUCTION At present a large amount of theoretical and experimental publications deal with water vapor (H 2 O) spectra in terahertzand infrared ranges. The results of some works are presented in well-known spectroscopic databases such asHITRAN2012 [1] and HITEMP2010 [2].The strong centrifugal distortion effects are inherent for H