Abstract: Due to their small size,peptide molecules exhibit farourablepharmacokinetic characterstics,such as rapid uptake by target tissue and rapid blook clearance,which potentiallyallowes images to be acquired earlier following the administration of a radiolabeled peptide radiopharmaceutical.The challenge is to label bioactive peptide with radioisotop with high specific activity without impairing the biological properties of the peptides.Molecular engineering technique now permits synthesis of a wide range of biologically active peptides that carry chelating groups in their structure without their receptor binding properties,thus permitting a high specific activity product.This article briefly summarized current experiments and clinicalapplication of the radiopharmaceuticals based on small receptor-binding peptides.The basic characteristics and the application of diagnosis and therapy with thrombus,infection/inflammation,and tumors are mainly reviewed.