Chronically reduced glomerular filtration rate (GFR) in old people does not always mean that they suffer from chronic kidney disease (CKD) since their GFR can just be reduced by aging. Measurement of GFR is recognized worldwide as the most accurate way of assessing renal function. GFR equations such as Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) are widely used to estimate GFR in the general population. However, because of the structural and physiological changes in the kidneys of the elderly, the common equations used to evaluate renal function are not entirely suitable for this population group. Therefore, we reviewed relevant literature in recent years, and made a systematic review on how to choose the glomerular filtration rate evaluation formula for the elderly.