Anhedonia is one of the core symptoms of depression, and it is also a difficult point in the treatment of depression. It is one of the important predictors for patients with long-term course, significant decline in quality of life and severe impairment of social function. Current research on the anhedonia phenotype of depression has provided important information for exploring the mechanism of its occurrence and development, but a complete and reliable etiological network has not yet been established, which limits the development of targeted therapy. Therefore, exploring the etiology of anhedonia phenotype in depression is of great significance for clinical treatment. This review summarizes the previous literature on anhedonia in depression, and introduces the research progress on the pathogenesis from the aspects of social psychological factors, physiological and biochemical factors, brain imaging, neural circuits and genetic inheritance.