We investigated 12 patents with idiopathic membranoproliferative glomerulonephritis. Discriminatory analysis was used for structural functional relationship in order to determine discriminatory power of certain clinical and pathohistological parameters. Semiquantitatively were determined pathohistological parameters: glomerular index in range 0-10, vascular index 1-4, interstitial fibrosis 0-10, interstitial infiltration 0-3, tubular atrophy 0-3. Nephrotic syndrome (symbolic value), quantitative proteinuria and creatinine clearance (continual variable) were used as clinical parameters. Discriminatory power was determined as a degree of decreasing Shennon's entropy dy distinction of patients according to value of creatinine clearance at the time of biopsy. Discriminatory power was measured in the information measurement units (bit). The most powerful was glomerular index (discriminatory power 0.29) in moderately reduced glomerular filtration rate (creatinine clearance 80 ml/min) at the time of biopsy. In severely reduced glomerular filtration rate (creatinine clearance 40 ml/min) vascular index had the greatest discriminatory power (0.24) while interstitial infiltration and interstitial fibrosis had less powerful discriminatory power (0.13). Negative predictive value of reduced glomerular filtration rate at the time of biopsy in membranoproliferative glomerulonephritis has been confirmed in other studies.