Abstract: A STUDY ON THE CONDITIONS OF THE METAIODOBENZYLGUANIDINE LABELLED WITH ~（131）I Chen Daming；Jin Xiaohai；Du Jin；Liu Yuemin；Wang Fan（China Institute of Atomic Energy，Beijing 102413）ABSTRACT A new rapid method of ~（131）I labelled MIBG（Metaiodobenzylguanidine）was described．The la belling efficiency is more than 97％using Cu（Ac）_2 as a catalyst，acetic acid，alcohol system as a medium of exchange reaction under the certain labelling conditions．The stability of labelled ~（131）I-MIBG cansatify the requirement of clinical application under the room temperature in a week．Key words ~（131）I-MIBG chromatographic analysis labelling