General principles of the surface plasmon resonance (SPR) phenomenon are applied to studying the structure and physical properties of thin conducting tin dioxide (SnO2) films. The SPR effects are detected and investigated by the methods of polarization modulation of the incident electromagnetic radiation. Angular and spectral dependencies of the reflection coefficients R-s(2) and R-p(2) for the s- and p-polarized radiation, together with their polarization difference rho = R-s(2)-R-p(2) are measured in the wavelength range of 400-1600 nm. Experimentally obtained rho(theta, lambda) characteristics reflect the peculiar optical properties associated with the film structure and morphology. Surface plasmon-polaritons and local plasmons excited by s- and p-polarized radiation were observed. The results confirm that the SPR technique is a sensitive and informative method for the analysis of the SnO2 film structure. (C) 2012 Elsevier B.V. All rights reserved.