A variety of methods for evaluation of renal function have been discovered, among which glomerular filtration rate (GFR) attracts much attention because of the major determinant of renal function. Recently, novel technique to evaluate glomerular filtration has been developed, including cystatin C, which reflects the changes in GFR at the earlier stage than serum creatinine. Furthermore, a progress has been made in evaluating tubular damage, with the discovery of N-acetyl glucosaminidase and liver-type fatty acid binding protein. More convenient and sensitive methods will be required to assess the changes in renal function in a clinical setting.