Abstract: Using chromatography for extracting medical isotope ⁹⁹Tc^m from ⁹⁹Mo is a potential way to deal with the current fission-based ⁹⁹Mo supply crisis. The process and properties of activated carbon fiber separating ⁹⁹Tc^m from mother nuclide ⁹⁹Mo were studied by static and dynamic adsorption experiments. The results show that activated carbon fiber can selectively adsorb pertechnetate ions in 3 mol/L NaOH solution. The equilibrium time is about 500 s, and the adsorption, with 32.47 mg/g of saturated adsorption capacity, follows the pseudo 2nd order kinetic model. In the dynamic adsorption elution experiment, the break-through volume of 1.0 g activated carbon fiber chromatographic column is 70 mL, and pertechnetate is effectively eluted from activated carbon fiber chromatographic column in 40 mL water. The research results show that chromatographic column of activated carbon fiber can be used for separation of technetium from molybdenum without organic solvent. The yield of technetium is 98%, and residual concentration of molybdenum is 3.5 mg/L in eluates.