Abstract: STUDY ON QSAR OF BRAIN RADIOPHARMACEUTICALS 0FIODOAMPHETAMINkSXU YEPING；LIU BOLI（Department of Chemistry,Beijing Normal University,Beijing, 100875）H.F. Kung（Department of Radiology,University of Pennsylvania P,A 19104,America）ABSTRACT According to the Fick＇s law，it is assumed that brain radiopharmaceuticals can pass throughBrain Blcod Barrier by simple diffusion process，After investigation of parameters of fourteeniodoamphetamines，a linear relationship among initial brain uptake，partition coefficient，proteinbinding and molecular weight has been established．This relationship may be useful in designingnew brain radiopharmaceuticals and predicting initial brain uptake. Key words Brain Radiopharmaceuticals Iodoamphetamine Structrue-activit Relationship