L-3[123I]iodo-methyltyrosine([123I] IMT) was synthesized by electrophilic radio-iodination using chloramine-T and Iodobead in phosphate buffered solution. And the biodistribution was examined in 9L glioma bearing rats. The radiosynthesis of [123I] IMT with iodobead was simpler and higher in radiochemical yield(88%) than the method using chloramine-T(83%) as radioiodinating reagent. The highest yield was obtained from the reaction using 1 piece of Iodobead, 200μg α- methyltyrosine in 100μl phosphate-buffered solution (pH 5.5) and the reaction was completed in 7min. 24hours after the injection, the biodistribution in 9L glioma transplanted rats revealed the in vivo deiodination, the excretion via kidney, and 3 times higher uptake in the tumor than normal brain. These results suggest the promising clinical use of [123I]IMT in the various ious malignancies.