Abstract: The enantiomeric ratio ( E ) is frequently used to characterize the enantioselectivity in enzyme-catalyzed kinetic resolution. In this paper two methods are evaluated in terms of accuracy, sensitivity towards E and its distribution.For the equation of Chen et al , the probability of r(ee_p)∈[0.5, 1.0], the influence on E of enanatiomeric excess of product ( ee_p), nearly reaches 0.75.The probability of r(ee_p)∈[0.7,1.0] exceeds one half.All r(ee_p) values are higher than 0.6 at conversion ratio ( C ) below 50%. For the equation of Rakels et al , the majority of r(ee_p) exceeds 0.6 when ee s, enantiomeric excess of substrate is lower and ee_p is higher.During the final phase of a reaction when ee_s is large, the changes of ee_s have greater effects on E than that of ee_p,but the probabilities for the above two cases do not exceed 0.5.In addition, there are quite a few situations in which r(ee_p) is equal to 0.4,0.5 and 0.6. This is the most distinguished discrimination of two methods and may also be the primary reason for which the latter is superior to the former.