The diffusion of adsorbed paramagnetic spin probes at the solid-liquid interface was studied using electron spin resonance spectroscopy (ESR) with 7-doxyl stearic acid as the probe. The changes in the localization of these probes at the interface was monitored by variations in the spin exchange line broadening of the ESR spectrum, These studies revealed that the introduction of fresh adsorption sites or a competing adsorbate causes a redistribution of the probe, However, temperature was found to have no significant effect on the probe localization.