Abstract: In vivo PET and SPECT imaging of β-amyloid (Aβ) plagques in the brain may lead to early detection of Alzheimer’s Disease (AD), but the Aβ-detector labeled by ⁹⁹Tc^m fell behind. The purpose of this study was to develop novel ⁹⁹Tc^m(CO)₃⁺-labeled β-amyloid-detector based on the flavones. Isostructural Re/⁹⁹Tc^m(CO)₃⁺-flavones were designed and synthesized, and Re(CO)₃⁺-flavone were studied on its binding characteristic with βamyloid plaques in vitro by fluorescence. The results showed that the binding affinity(K_d=5.43 nmol/L) of Re(CO)₃⁺-flavone was higher than flavone derivatives labeled by radioiodine. The biodistrubution of normal mice showed that ⁹⁹Tc^m(CO)₃⁺-flavone displayed moderate uptake （0.46±0.23%ID/g） at 2 min postinjection) in the brain and rapid clearance （0.13±0.04%ID/g) after 120 min injection. The above results demonstrated that ⁹⁹Tc^m(CO)₃⁺-flavone should be desirable as a potential SPECT imaging agent for β-amyloid aggregates.