Abstract: The intestinal microecosystem is composed of natural microflora,intestinal epithelial cells,and intestinal mucosal immune system.Nonalcoholic fatty liver disease(NAFLD) is a metabolic stress-induced liver injury associated with insulin resistance and genetic susceptibility.In recent years,there has been increasing evidence showing the involvement of imbalanced intestinal microflora in the pathogenesis of NAFLD.Overgrowth of intestinal microflora,increased permeability of intestinal mucosa,intestinal endotoxemia,and production of inflammatory cytokines play important roles in the development of NAFLD.Further studies on the relationship between intestinal microflora imbalance and the pathogenesis of NAFLD may shed light on the treatment and prevention of NAFLD.