The structures and properties of BR/CR/SBS blends were studied by using optical, electron microscopy, FTIR methods, etc. Results showed that the addition of a small amount of SBS to the thermodynamically immiscible blends BR/CR could significantly promote fine and homogeneous dispersion of the system, increase crosslink density of vulcanizates and tensile strength, and decrease loss of tan delta of the blends. IR spectra also demonstrated the stronger interaction between SBS and BR, CR. The theoretical prediction of compatibilizing activity of SBS in the BR/CR blends is in excellent agreement with experimental results.