Intestinal flora plays an important role in promoting digestion,maintaining intestinal physiological function and regulating immune system. In recent years,it is found that intestinal flora not only regulates intestinal activity,but also affects the brain function and behavior. Early studies have shown that changes in probiotics may lead to alteration in brain function and mood. Studying the influence of intestinal flora on brain function helps us to catch on the pathogenesis of mental disorders such as autism,and expand our comprehension on the mechanism of brain activity as well. This article reviewed the advances in study on affecting pathway of intestinal flora on brain.