The most common electrolyte disorder in clinical small cell lung cancer（SCLC）is hyponatre⁃ mia. Syndrome of inappropriate secretion of Antidiuretic hormone（SIADH）is the main part of this study，and exploring the mechanism is helpful for diagnosis and treatment. It is still necessary to further explore whether tolvap⁃ tan and other treatment plans are more advantageous in normalizing hyponatremia. The choice of different therapeu⁃ tic strategies，such as urea，circulating diuretics，demecycline，lithium，amrubicin and tolvaptan，may improve the prognosis of patients. This article will review the treatment plan and prognostic factors of SCLC complicated with hyponatremia in recent years.