Objective To study the application of 99Tcm in rabbit cerebral thromboembolic stroke and thrombolysis effect of recombinant tissue plasminogen activator (rt-PA).Methods The 0.5 mL radioactive pertechnetate sodium (specification:5 mCi/2mL and radiation intensity 92.5 MBq/mL) was combined with 30 μL stannous chloride (5 mg/mL),and the 20 μL mixture was joined to whole blood,red blood cells,and plasma for labelling.Then 50 μL CaCl2 (0.5 mol/L) and bovine thrombin (50 IU/mL) were doped in mixture,and rapidly sucked into a polyethylene plastic pipe (PE80).Thrombus was formed for 2 h at 37 ℃ and cut into small pieces of 10 mm.Autologous blood clots combined with 99Tcm from external carotid artery were injected to internal carotid artery of rabbit,the radioactivity (counts per minute,CPM) was measured by gamma counting instrument,and the improvement of rt-PA 4.5 mg/kg (clinical equivalent dose) on this model was observed.Results After thromboembolism,CPM increased approximately by (5.1 ± 1.3) times,which suggested that the model was reliable.The rt-PA 4.5 mg/kg had significant progressive thrombolysis effect.Conclusion 99Tcm tracer technology could be applied to rabbit cerebral stroke model,which is stable and reliable