Raman spectroscopy is a promising tool for measuring the composition of natural gas. However, to obtain high measurement accuracy, it is necessary to take into account changes in the spectral characteristics of methane, since its spectrum overlaps the characteristic bands of other species. In this study we present a technique for natural gas analysis based on polarized Raman spectroscopy. It is shown that the use of only isotropic components of spectra simplifies the procedure for extracting concentrations and improves the measurement accuracy of components whose spectral bands are significantly overlapped in conventional Raman spectra. The presented technique will be very useful both in the field of analysis of various multicomponent gas mixtures and in the field of measuring the isotopic composition of molecules.