Stable gut micro-ecology is an important guarantee and necessary condition for maintaining human health. The imbalance and disorder of gut micro-ecology are related to the occurrence and development of many diseases，and its relationship with intestinal diseases is particularly close. Radiation enteritis is a radiation injury of the intestines in patients with abdominal and retroperitoneal malignant tumors after radiotherapy. The process of is occurrence and development is complex，and gut micro-ecological imbalance is an important factor in the formation of the disease. Effect of conventional drug treatment effect is very limited for radiation enteritis，and therapies focusing on gut micro-ecology has shown better therapeutic effect and safety. Therefore，this paper reviews the mecha－nism of the influence of gut micro-ecology on the development of radiation-induced enteritis in hope of providing a basis for the clin－ical treatment of radiation enteritis via regulation of gut micro-ecology.