Abstract: The anion-exchange behaviour of molybdenum (VI), tungsten(VI) and other metal ions on a strong basic anion-exchange resin (Zerolit FF) has been investigated in oxalic acid-hydrochloric :acid system. There are marked differences in adsorptivity for molybdenum(VI) and other metals. The optimum condition for separation is to keep the solution at 0.05Moxalic acid-1.0Mhydrochloric acid. Using a strong basic anion exchange column in the chloride form, tungsten(VI) and other metal ions pass through while molybdenum(VI) is quantitatively retained as oxalate complex.Then molyb-denum(VI) is eluted with 1.0.Mhydrochloric acid. Acolumn 2cm long diameter 0.9 cm is satisfactory for the separation of microgram quantity of molybdenum (VI) from sodium tungstate(reagent grade). The system offers a good method for preparation of tungsten without molybdenum.From the slope of the plot of distribution coefficient against concentration of chloride ion in the system, it has been shown that for molybdenum only one kind of complex ion, MoO₃ (C₂O₄)₂^2-, is predominant and governs the exchange mechanism.