Purpose To explore whether potassium perchlorate shall be taken orally to occlude gastric mucosa before taking 99Tcm-3PRGD2 SPECT/CT gastric image,and to provide theoretical evidence for clinical application.Material and Methods Eighteen adult male Wistar rats were divided into three groups randomly:low dose group of potassium perchlorate (36 mg/kg),high dose group (72 mg/kg) and normal saline control group,with six rats in each group.All rats were conducted with gavage of 1 ml/100 g respectively and,one hour later,injected with 99Tcm-3PRGD2 intravenously to rat tail.Then 99Tcm-3PRGD2 gastric image was taken two hours later.The same film reader carried out audio analysis of the image and then gastric and radioactivity ratio (T/N) on the lung of the same side were analyzed.Results Preparation of 99Tcm-3PRGD2 was simple and radiochemical purity of final products was (98.90±0.70)％.Rat weights in high dose group of potassium perchlorate,low dose group and control group were (479.7t21.5) g,(481.0± 17.6) g and (478.5± 16.5) g,respectively.The differences were of no statistical significance (F=0.027,P＞0.05).T/N values in rat stomach area were 1.2219±0.0165,1.2204±0.0167 and 1.2186±0.0175,respectively.The differences were of no statistical significance (F=0.055,P＞0.05).Conclusion Preparation of 99Tcm-3PRGD2 is simple and radiochemical purity is high.There is great possibility of no need to take potassium perchlorate orally to occlude gastric mucosa when taking 99Tcm-3PRGD2 SPECT/CT image (especially when the radiochemical purity of final products is over 98％),making it convenient in clinical promotion and utilization.