||The kinetic properties of several (alpha)-cyclodextrin-azo dye complexes were examined by means of a temperature-jump method. Kinetic evidence and theoretical considerations showed that complexes of certain dyes with (alpha)-cyclodextrin undergo conformational changes. The binding and light absorbance equations for interactions of ligands with proteins possessing multiple binding sites were derived and the binding constants of some azo dyes to bovine serum albumin were measured using a spectroscopic technique. Several properties of (alpha)-cyclodextrin and bovine serum albumin systems were compared with each other. This comparison shows that (alpha)-cyclodextrin can be used as a model to investigate various aspects of protein-ligand interactions.