Hydroformylation of 1-dodecene catalyzed by water-soluble rhodium-phosphine complex, RhCl (CO) (TPPTS)2 (TPPTS: P(m-C6 H4 SO3 Na)), in the presence of various mixed micelles was investigated. When either an anionic surfactant sodium dodecyl sulfate (SDS) or dodecylbenzonesulphonate (DBS), a nonionic surfactant Triton X-100 or Brij 35, or alcohol was added into cationic surfactant cetyl pyrindium bromide (CPB) solution, a mixed micelle formed. The decrease in critical micelle concentration (CMC) and the increase in solubilization of 1-dodecene in the mixed micelle were observed. Hydroformylation of 1-dodecene exhibited higher conversion and higher regioselectivity in the mixed micellar solution than in the single micelle of CPB. The synergistic mechanism of two different surfactants was discussed.