Abstract: Insulin-like growth factor-1(IGF-1) mediates the growth-promoting effect of growth hormone on peripheral tissues, which is mainly synthesized in the liver. In the circulation, most IGF-1 binds to specific binding proteins, which is more stable than growth hormone. Therefore, IGF-1 is commonly used as a diagnostic marker and treatment monitor of growth hormone deficiency and acromegaly. There are many kinds of assays that measure serum IGF-1 concentrations, including radioimmunoassay, ELISA, chemiluminescence, and mass spectrometry. Different methods have their advantages and disadvantages, so it is necessary to select the best method according to the purpose of detection. The normal reference range of IGF-1 should be established based on a random sampling of the background population. Some European and Asian countries such as Germany, Italy, Japan, and South Korea have established reference ranges of serum IGF-1 based on their own population. ZHU Hui-juan et al. from Peking Union Medical College Hospital preliminarily established the reference range of serum IGF-1 of Han Chinese adults, laying a foundation for the diagnosis and treatment of acromegaly, growth hormone deficiency, and other diseases.