One method has been developed to separate niobium (V) and tan-talum (V) by means of liquid surfaetant membranes containing sec-oc-tyl alcohol as carrier mediation.The emulsion membrane systems con-sisting of kerosene,sec-octyl alcohol and shangan (N 205) can rapidlyand effectively separate Nb (V) and Ta (V ) mixtures,only if the con-ditions of sources phase has been well controlled.We can find thatTa (V),for the 500 ppm Ta_2O_5 in the sources phase,can almost beextracted,while the extraction rate of Nb (V) ...