Diabetes mellitus is a chronic, systemic, metabolic, and progressive disease characterized by elevated blood sugar, and is a disorder of sugar, fat, and protein metabolism caused by defects in insulin secretion and/or action. Following the discovery in 1987 that GLP-1 could promote insulin secretion, an incretin analog Exendin-4 with 53% homology to GLP-1 was isolated from the saliva of Mexican monitor lizards five years apart. - The later exenatide, which possesses GLP-1 receptor agonistic activity and has a long half-life. In 2005, the FDA approved exenatide injection (Byetta®) for the auxiliary control of blood sugar in patients with type 2 diabetes who cannot be controlled by oral hypoglycemic drugs. The listing of exenatide has boosted the research and development of GLP-1 receptor agonists, and the advantages of GLP-1 receptor agonists have become increasingly prominent.