Abstract: The relations of the distribution ratios of Fe(Ⅲ), Mn(Ⅱ), Cu(Ⅱ) and Co(Ⅱ)in aqueous and organic phases to the acidity, the concentration of isopropyl etherand tributyl phosphate(TBP) and the volume ratios between isopropyl ether andTBP are studied. When the mixed solution of Fe(Ⅲ), Mn(Ⅱ) and Co(Ⅱ) in4mol/l HCl medium is extracted by isopropyl ether-TBP, the distribution ratioof Co(Ⅱ) is less than 0.1, i. e. the loss of Co(Ⅱ) is 1owered to the mini-mum, and that of Fe(Ⅲ) is equal to 15, that is, enhanced considerably. Afterthe solvent extraction, further enrichment and separation of Co(Ⅱ) are carriedout by anion exchange. The mean value of the measured recovery for Co(Ⅱ) is93+7%. The contents of impurity elements in 93μg of Co(Ⅱ) are as follows:Fe(Ⅲ) 2.0 μg, Mn(Ⅱ) 0.0 μg, Cu(Ⅱ) 0.0μg. The bombardment of the irontargets is performed in a 120 cm cyclotron, on the external and interna1 targetassemblies, with 12.5 MeV and 8.0 MeV deuterons, respectively. The cumulativebeam intensities are 128 μA·h and 50 μA·h, respectively. After cooling, theisotopes of Co(Ⅱ), i. e. ~(57)Co, ~(56)Co and ~(58)Co are separated from ~(54)Mn, ~(59)Fe and~(63)Cu or Cu(Ⅱ) using the method of isopropyl ether-TBP solvent extraction andanion exchange. A sample of 100 μl taken from the separated solution is driedby heating and the measurement of γ-spectrometry is carried out by means of aGe-Li detector combined with a pulse amplitude analyser with 4096 channels. Itis shown that the bombardment of iron targets by 8.0 MeV deuterons produced~(57)Co of higher purity in which ~(58)Co amounted to only 8% and no other radioac-tive impurities including ~(56)Co are detected. The result obtained in this way issatisfactory.