The transport rates of europium(III) through a supported liquid membrane (SLM) containing di(2,4,4-trimethylpentyl)phosphinic acid as a mobile carrier were analyzed. First, the batch extraction equilibrium of the title system was investigated and the equilibrium constants for the formation of the extracted complexes were determined. Second, an SLM transport model was presented considering diffusion of metal across the feed stagnant layer, chemical reaction of metal and carrier at the feed-membrane interface, and diffusion of carrier and its metal complex in the membrane phase. The kinetic parameters of the complex formation reaction were evaluated from the SLM transport data. Moreover, the transport mechanism was identified quantitatively by calculating the fractional resistance of each step during transport.