Abstract: IgA nephropathy (IgAN) is the most common primary glomerular disease worldwide. The hallmark of the disease is that IgA immune complexes predominantly deposit in the glomerular mesangium, and the IgA containing deposition induces activation and proliferation of mesangial cells which release inflammatory cytokines and chemokines to mediate inflammation in glomerulus. Diagnosis of IgAN still depends on renal biopsy. In this review, we introduce advances in the pathogenesis of IgAN including the key molecular events in generation of aberrantly glycosylated IgA1 and autoantibodies to them, the formation of circulating IgA immune complexes, deposition of immune complexes in the glomerular mesangium, and inflammation in glomerulus induced by IgA immune complexes, as well as the large scale genome-wide association studies in patients with IgAN from Asian, European, and American populations. At last, recent studies on the emerging biomarkers with diagnostic and prognostic potential for IgAN will be introduced.