The effect of TPPTS [p(m-C6H4SO3Na)(3)], RhCl(CO)(TPPTS)(2) and olefin on CMC (critical micelle concentration) of the aqueous solution containing cationic surfactant cetyltrimethylammonium bromide (CTAB) was studied by the maximum bubble pressure method. The apparent molar mass of micelle was determined by a light scattering method. The results showed that the addition of TPPTS and RhCI(CO)(TPPTS)(2) into aqueous solutions of CTAB caused the decrease of CMC and the increase of the apparent molar mass of micelle. The data supported the suggestions about enrichment of rhodium catalyst in micelle interface layer and about the solubilization of olefin in micelle. This explanation was confirmed by the measurements of rhodium concentration in the interface layer using ICP method. The acceleration mechanism of long chain olefin hydroformylation in a biphasic catalytic system containing a cationic surfactant was provided.