The complexation properties toward adamantane-grafted chitosan of two P-cyclodextrin (CD) homodimers, containing two CD moieties that are linked through their primary sides by one or two aliphatic spacers, are studied by rheological and dynamic light scattering measurements. Very different behaviors are observed between these two CD molecules which can be related to different molecular flexibilities and inclusion properties of their cavities. These results show that a subtle change in the molecular architecture of such CD dimers dramatically changes their ability to physically cross-link modified chitosan chains.