Renal biopsy specimens of 13,519 cases were collected during the period of January 1979 to December 2002 from the Research Institute of Nephrology, Nanjing University School of Medicine, Nanjing, China. Analysis of the data of this group of patients showed that primary glomerulonephritis (GN) remained the most important and prevalent renal disease in China. The ratio of primary to secondary GN was 2.75:1. However, it is declining progressively in the past two decades with an increment in the incidence of diabetic nephropathy and nephrosclerosis. IgA nephropathy (IgAN) constituted 45.26% of the primary GN, while non-IgA mesangial proliferative lesions were 25.62%. Membranous nephropathy was 9.89% and minimal change disease was 0.93%, remarkably less. The most prevalent etiology of secondary GN was systemic lupus erythrematosus (SLE) (54.3%) followed by Henoch-Schönlein purpura (20.3%), diabetic nephropathy (6.6%), systemic vasculitides (4.0%), and amyloidosis (2.2%). Based on the study of biopsy materials obtained from 607 cases manifesting chronic renal failure, IgAN was identified as the most frequent cause (26.69%) of chronic renal failure.