Abstract: The direct labeling method of octreotide with 99 Tc m is established. The labeling yield of 99 Tc m octreotide is 78.5% and radiochemically purity is 93.8% after purification. The 99 Tc m octreotide compound remained stable for at least 4 h at room temperature or incubated with DTPA、HSA、 L cysteine for 4 h at 37℃. These results show that 99 Tc m octreotide is a promising somatostatin receptor imaging agent.