Objective To investigate the clinical characteristics and causes of misdiagnosis of patients with IgA nephropathy,so as to improve the diagnosis of IgA nephropathy.Methods 85 patients were diagnosed as IgA nephropathy by renal biopsy,the clinical data of them were analyzed retrospectively.Results In 267 patients with primary glomerular diseases,85 cases(31.38%) were IgA nephropathy and 30 cases of them(35.2%)were misdiagnosed as other renal diseases.Conclusion Clinical manifestations of IgA nephropathy were mulriple and it was prone to be misdiagnosed.Immunopathology of the kidney biopsy is the best way to be diagnosed definitely and avoid misdiagnosis.