IgA nephropathy (IgAN) is the most common primary glomerular disease that can result in end-stage renal disease, and is histologically characterized by the deposition of IgA1 in the glomerular mesangium. The abnormal IgA1 glycosylation is the key factor in the pathogenesis of IgAN. Multiple genetic loci associated with IgAN have been identified, and the cytokines coded by them are involved in the pathopoiesis mechanism of abnormal IgA1 glycosylation. In addition, the lack of glycosylase and abnormal methylation of molecular chaperone may also be involved in the aberrant glycosylation of IgA1. Abnormally glycosylated IgA1 can deposit in the mesangium through their own assembly together or formation of immunocomplex, which can subsequently stimulate mesangial cell proliferation and secretion of extracellular matrix, cytokines, chemokines, and growth factors, etc, leading to glomerular injury. In-depth research on IgA1 abnormal glycosylation will help to understand the pathogenesis of IgAN and provide new diagnosis and treatment methods.