We have measured the temperature raised by laser irradiation on the basis of difference between Stokes and anti-Stokes Raman scattering cross-sections, and further estimated the thermal conductivity of the material. GeSbSe glasses with compositions of GexSb10Se90-x, GexSb15Se85-x, and GexSb20Se80-x are systematically studied with the aim of verifying the practicability of the new method and understanding the role of chemical composition in determining the structure and thermal conductivity of the glasses. All of the results are in agreement with those reported on thermal conductivity measured by different methods in the literature. It is indicated that Raman scattering method is convenient and efficient to measure thermal conductivity of the materials. For each group of glasses, it is found that the thermal conductivity increases with increasing Ge concentration up to a transition point corresponding to the glass with chemically stoichiometric composition. We ascribe the threshold behaviour of the thermal conductivity to the demixing of the structural units from glass network.