Abstract: Neuroendocrine tumors (NETs) are a type of heterogeneous malignancies originating from the neuroendocrine system. Well-differentiated NETs can express high levels of somatostatin receptor (SSTR). Radioisotope-labeled somatostatin analogue can realize functional imaging in NETs by specifically binding to SSTR, which is crucial for the diagnosis and clinical management of NETs patients. In recent years, a variety of tracers targeting SSTR have been developed successfully, paving the avenue towards the precision medicine in NETs. The authors summarizs the development of SSTR imaging agents for SPECT or PET and their clinical applications in NETs.