Tetraalkylammonium (TAA) salts of transition metal substituted dodecatungstophosphate, (TAA)(5)PW11O39.H2O (where TAA = (C2H5}(4)N (TEA) (C3H7}(4)N (TPA), and (C4H9}(4)N (TBA), and M = Mn2+, Fe2+ and Co2+) catalyzed the oxidation of styrene with H2O2 at 353 K. Except for the Mn2+ salt, other TAA salts were found to be active and gave mainly benzaldehyde and styrene oxide products. Among the catalyst tested, TBA (tetrabutylanunonium) salt of Co2+ was more active in styrene oxidation. Kinetics of TBA-PW11CoO39 catalyzed oxidation of styrene have been investigated and mehanism for oxidation of styrene has been proposed.