The synthesis and biodistribution of β-amyloid plaques imaging agent [¹³¹I]-2- (4′-dimethylaminophenyl)-6-iodoimidazo[1,2-α] pyridine ([¹³¹I]IMPY) were reported. The chemical structure of the labeling precursor 2-(4′-dimethylaminophenyl)-6- (tributylstannyl) imidazo[1, 2-α] pyridine and all its intermediates were verified by IR,HNMR and MS. The radioiodinated compound was prepared using iododestannylation reaction by hydrogen peroxide. Final radiochemical purity was above 95% determined by TLC. The in vivo biodistribution of [¹³¹I]IMPY in normal mice showed excellent brain uptake and washout, indicating this thioflavin-T based small molecular probe has potential for in vivo imaging amyloid deposits.