Abstract: Octreotide can be labelled with ¹⁸⁸Re by using the direct labelling approach and the bifunctional chelate approach.The direct labelling approach concludes pretinning procedure and two-step reduction method.By pretinning pro-cedure,both octreotide and perrhenate are reduced by SnCl₂.Rhenium of a lower oxidation state is bound to octreotide directly.By two-step reduction method,octreotide and the perrhenate are reduced by different reduction agent respectively.The direct radiolabelling approaches allow very high radiochemical purity,high specific activity formulation,low radiocolloid formation and good in vitro stability,without the need for post-radiolabel ling purification to eliminate the un-bound free radioisotope.A kit could be developed which would merely require the mixing of perrhenate with the other reagents in a single vial.