Protein adsorption from aqueous solution is determined by a "match" between two interfaces, one between the protein and the aqueous solution and the other between the adsorbent surface and the solution. A subtle interplay between polar and non-polar interactions regulates protein stability and plays a decisive role in protein interactions with the adsorbent surface. Other factors include the adsorbent's surface energetics, charge, rugosity, and the structure of water at both interfaces, i.e. their respective hydrophilicity and interfacial hydration layers. In order to characterize and predict protein adsorption, one seeks information about adsorption isotherms and kinetics, conformation of adsorbed proteins, number and character of surface-bound pr otein segments, and the physical parameters describing the adsorbed protein layer. The most powerful techniques for protein adsorption studies include optical and spectroscopic methods. These methods can provide insight into protein concentration, confor m ation and dynamics at interfaces. We have designed a spatially-resolved total internal reflection fluorescence spectroscopy method (1-D TIRF) to measure competitive adsorption kinetics of human plasma proteins. When combined with autoradiography and sur fa ce hydrophobicity gradients, 1-D TIRF experiments provide a quantitative description of protein adsorption and desorption kinetics as a function of surface hydrophobicity. As an example we will show the analysis of the adsorption kinetics from a binary so lution mixture of human serum albumin (HSA) and human low density lipoproteins (LDL) onto the model surface with a density gradient of octadecyldimethylsilyl chains on fused silica (C18-silica gradient). The adsorption and desorption rate constants are obtained by fitting the experimental results to an adsorption model that accounts for the mass transport effects and the surface density of the C18 groups.