Abstract: The extraction kinetics of uranium(Ⅵ) with the binary extractant sytstem of trioctylamine (TOA) and tri n octylphosphine oxide(TOPO) in n heptane from sulphuric acid media is studied using stationary interface stirring cell at 298 K. The synergism mechanism is reported that there are two step continuous reaction at the interface. The influence of temperature on the extraction rate is investigated. The activation energies( E f and E b) of the possitive and inverse reactions are calculated.