1D and 2D H-1 NMR studies of anthraquinone-2,6-disulfonic acid disodium salt in the beta-cyclodextrin solution have identified the inclusion complex formation. The association constant of AQDS-beta-CD inclusion complex was determined as 800 +/- 100 M-1. The selective intra-complex photo-oxidation of beta-cyclodextrin at C6 position was detected by CIDNP method. (c) 2005 Elsevier B.V. All rights reserved.