The gross structure of turbulent jet diffusion flames developing in a coflowing high temperature vitiated air stream was examined experimentally and theoretically. The observed radial profiles of total pressure within the flame were similar in all axial positions, while the temperature profile showed a sharp peak at the most luminous position. The measured temperature profiles in the upstream region of flame were found to correlate satisfactory with those of a simplified analysis based on the flame surface approximation and the boundary layer similar solution for the velocity field.