The kynurenine pathway, a major route of tryptophan metabolism, is involved in the occurrence and development of some neurodegenerative diseases, such as Huntington's disease, Alzhermier's disease and Parkinson's disease. This article is focused on the literature review on the neurobiological properties of kynurenine pathway metabolites and their crucial role in related neurodegenerative diseases, for providing novel therapeutic interventions to neurodegenerative diseases.