Abstract: Computer imaging analysis system was utilized to study retrospectively the relationship betweenfibrin related antigen（FRA）deposition in glomeruli and the clinicopathological manifestations in patients withlgA nephropathy.Results showed:（1）FRA deposition in glomeruli was very common in patients with IgAnephropathy,with a prevalence of 61%,only less than those of IgA and C₃;（2）FRA deposition in glomeruliis related to proteinuria and serum creatinine level,as well as glomerular mesangial sclerosis. FRA depositedin glomeruli may well take a part in the clinicopathological process of IgA nephropathy.