[en] 3'-Deoxy-3'-Fluorothymidine (¹⁸F-FLT) is synthesized by 'BAThy' method at Tracerlab FX_f-N system. By using 5'-O-benzoyl-2,3-anhydro-thymidine (BAThy) as the precursor, ¹⁸F-FLT is obtained by two step reactions, including the nucleophilic fluoration and hydrolysis. The synthesis can be completed about 50 min. The radiochemical yield and radiochemical purity are about 10% and 95%, respectively. The procedure is guide simple and automated synthesis. (authors)