Abstract: Annexin V is labeled with ~(125)I by using Iodogen method and the biodistribution of which in mice is investigated.The labeling yield of ~(125)I-Annexin V is 94.9% and its radiochemical purity is over 99% after parification.The radioactivity uptake is the highest in kidney,followed in order by blood,liver,heart,lung and spleen;no uptake in brain;the lower in muscle and bone;The uptake of the selected tissues is decreased rapidly at 1 hour after injection except blood.The results show that it is a excellent imaging agent for diagnoses.