CKD is now recognized as life-threatening disease and various countermeasures are implemented worldwide. The most important step to overcome CKD is early detection and evaluation. Equation for estimating GFR is the necessary tool for this step. This is also useful to follow-up CKD patients in routine clinical settings. Currently, most commonly used equation is original and re-expressed MDRD formula. For Asians, ethnic co-efficient is needed when applying these formulas. Ethnic co-efficient is different among Asian countries. Recently, different original equations have been developed in several Asian countries. At the present time, it is not clear to develop a single common eGFR equation fit for Asians. There are several factors that affect GFR estimation. These include ethnicity, reference method to measure GFR, method of creatinine measurement and calibration. Towards the future, Asian collaborative study is necessary to validate and standardize eGFR equations.