Objective: To raise awareness of pathogeny, diagnosis and treatment of eosinophilic gastroenteritis in infants. Methods: The clinical data of one eosinophilic colitis infant with exclusively breast-fed were reported and relevant literature were reviewed. Results: 49-day-old male exclusively breast-fed infant who had a family history of allergic diseases, sought a doctor for diarrhea, eczema, vomiting and edema; With malnutrition, ascites, anemia, hypoproteinemia, elevated eosinophils and elevated total IgE in peripheral blood; Pathological examination of the colonic mucosa showed eosinophilic infiltration. The infant improved significantly after treating with diet avoidance (changed breastfeeding to amino acid milk powder) and hormone. Conclusions: The clinical manifestations of eosinophilic gastroenteritis are lack of specific, the clinical doctors should combine the history of allergic diseases and improve the pathological examination of enteroscopy and intestinal mucosa as soon as possible when it is difficult to diagnose. When looking for allergens, breast milk should not be ignored; Diet avoidance should be given in time and the therapeutic effect is better.