Abstract: The separative conditions of 199T1 from Cu、Au and Ga by reaction 197Au (α,2n)199Tl on the internal target installation of cyclotron is studied. The a-particle energy is selected in the range of 24-25 MeV. The cumulative current intensities of such a-particle beams bombarding the gold target at 150-200μA are 1200μA·h and 1500μA· h respectively. The radiochemical separation of 199Tl is carried out with isopropyl ether extraction and anion exchange from the irradiated gold targets. The radioactivities of 199Tl and 200Tl are 2. 3×105Bq and 7. 1×102Bq,and 200Tl makes up 0. 29% of the total radioactivity. The impurity elements contained 1ml of 199TlCl injection solution are Au<0. 2μg,Cu<0. 04μg,Fe=0. 166μg,and Ga=0. 00μg. 199TlCl has been used in clinical experiments in vivo and relatively good results have been obtained.