The international standardization of criteria for the histologic diagnosis of renal allograft rejection was estabilished in Banff, Canada on August 1991 to promote international uniformity in reporting of renal allograft pathology, facilitate the performance of multicenter trials of new therapies in renal transplantation. In this schema acute and chronic rejection were graded by the histologic severity of rejection. The author examined the clinical status(serum creatinine, delta creatinine, the amount of urinary protein excretion) at the time of biopsy and graft survival after biopsy according to the grading of rejection to assess the clinical validity of Banff schema in patients with biopsy-proven graft rejection. In the patients with biopsy-proven chronic rejection, the serum creatinine(p=0. 0046) and delta creatinine(p= 0.0025) were statistically correlated to the grading of chronic rejection. The histologic severity of chronic rejection has no impact on the amount of urinary protein. The amount of urinary protein excretion is closely linked to the type of as- sociated glomerular lesions such as transplant glomerulopathy or membranous glomerulonephritis with which the patients had nephrotic range proteinuria. In 18 patients with biopsy-proven acute rejection, the clinical correlation was statistically not significant in this study. In the patients with mild degree chronic rejection, superimposed acute rejection on chronic rejection has poorer prognosis than chronic rejection without acute component.