The liquid-solid extraction behaviour of the Cu(II), Co(II), Ni(II), Zn(II), Cd(II) and Mn(II) in ammonium sulfate-carboxy-2'-hydroxy-5'-sulfoformazylbenzene (zincon)-Tween 80 system was investigated. The results indicated that the complexes of Cu(II), Co(II), Ni(II) with Zincon were almost completely extracted in buffer solution (pH 6-9) by Tween 80 phase while those of Zn(II), Cd(II), Mn(II) were not. Quantitative separations of Cu(II), Co(II), Ni(II) from mixed ions of Zn(II), Gd(II), Mn(II) in different pH buffer solution were realized.