A lot of progress has been made after 50 years of researches on IgA nephropathy (IgAN). It has been gradually realized that IgAN is a chronic progressive disease, with many factors playing key roles in its development and progression, including mucosal immune abnormalities, abnormal glycosylation of IgA1 and its antibody production, as well as deposition of immune complexes in the glomerular mesangial area, which subsequently activates the complements, promotes the glomerular inflammation, proliferation, and sclerosis. Therapies with renin angiotensin system (RAS) blockers have shown renal protective effects, although there have been no conclusions in many aspects yet. The authors mainly combed through the latest literature and personal clinical experience to summarize the relevant progress of researches on IgAN biomarkers, pathological diagnosis, immunosuppressive therapy, and tonsillectomy, etc, so as to meet the needs of readers.