The application of homogenizing agent H40MSF in the inner liner compound of steel- belted radial tire was investigated. The results showed that, by using H40MSF to replace homogenizing agent 40MSF at the same addition level in the inner liner compound,the mixing energy consumption of the compound decreased, and the production efficiency increased. The curing behavior of the compound,the dispersion of carbon black and physical properties of the vulcanizate changed little. The endurance and high speed performance of the finished tire were improved.