Abstract: Small cell lung cancer is neuroendocrine neoplasm and origins from APUD (amine precursor uptake decarboxylation) cell. Somatostatin receptors (SSTR) are highly expressed on the surface of tumor cell. Octreotide is an analogue of somatostatin consisting of 8 amino acids, which with a similar bioactive structure not only has stronger biologic effect and longer biologic half life but also is less susceptible to degradation. Tumor receptor imaging with isotope labeled octreotide is a suitable noninvasive technique in the diagnosis of small cell lung cancer.