Abstract: As a key signal transduction molecule involved in the innate immune response, stimulator of interferon genes (STING) is triggered by cytosolic DNA from pathogen and host origins, and plays an important role in inducing the secretion of type I interferons and proinflammatory cytokines, thereby defending against viral and intracellular bacterial infections and regulating the production of spontaneous antitumor immune responses in vivo. Thus, STING agonists have shown useful therapeutic effects for pathogen infection and cancer. In the past decade research on STING and its agonists has progressed rapidly. Here, we summarize recent advances in the structure and activation of STING and the mechanism of the cGAS-STING pathway. In particular, we review research advances of STING agonists, analyze the crystal structure of STING in complex with its agonists and the structure-activity relationship of STING agonists, and summarize the strong challenges of developing STING agonists.