The disssociation kinetics of alximinum-fulvic acid (Al-FA) as a function of the concentration of fulvic acid, pH, and ionic strength were studied with a fluorescence ligand exchange method using lumogallion. A graphical method and statistical non-linear regression were used for analyzing kinetic data. A two component, five parameters model appeared to fit the data best. For a fixed aluminum concentration, dissociation rates decreased as the concentration of fulvic acid increased and a greater fraction of the total aluminum appeared in the most slowly dissociating component. Increasing pH slightly decreased the dissociation rate. Ionic strength appeared to have no effect. The estimated pseudo-first-order dissociation rate constants for the two components were about 0.1 and 0.01 min(superscript)-1 respectively.