Abstract: Intestinal microecology is a complex microbial system. Diarrhea is the most common clinical symptoms in digestive disease, which is caused by viruses, bacteria, parasites or other microorganisms and their products. Diarrhea may be associated with intestinal dysfunction, intestinal flora imbalance, immune imbalance and vasculitis. In recent years, microecological agents play important roles in the treatment of diarrhea and they have made many progresses. In this review, we discuss the relationships between intestinal microecology, probiotics and treatment of diarrhea.