Three methods to determine UNIFAC parameters by chroniatography have been compared. The method of multiple activity coefficients at infinite dilution has been found inferior to the other two methods. According to an analysis on the sensitivities of UNIFAC parameters to γ∞ and (dγ/dx)x=0
it has been discovered that the effect of γ∞ is greater than that of(dγ/dx)x=0. Estimates of parameters and their ranges of values above an appropriate confidence level are discussed.