Abstract: The experimental investigation of erosive burning in one lobe of the star core grain in a solid propellant rocket engine was carried out.The experimental results show that the erosive burning rate in the star recess is higher than that at the star point.The nonuniformity of erosive burning is dependent on the average flow velocity parallel to the burning surface,the chamber velocity parallel to the burning surface,the chamber pressure and the geometry of the cross section.From comparison between the calculational results and experimental data it is concluded that the nonuniformity of the erosive burning comes mainly from the nonuniformity of the velocity distribution.