Abstract: The pathogenesis of ulcerative colitis （UC） remains elusive, which is probably correlated with multiple factors, such as heredity, immunity and environment, etc. DNA methylation plays an important role in regulating gene transcription, development, differentiation and genomic stability. Aberrant DNA methylation is not only a consequence of chronic intestinal inflammation, but also may play a role in the occurrence and development of UC. In this article, the possible mechanism and clinical significance of aberrant DNA methylation in UC were reviewed.