It was reported that polyrotaxanes (PRs) comprising beta-cyclodextrins (beta-CDs) and Pluronic F127 end-capped with poly(N-isopropylacrylamide) blocks show a beta-CD aggregated state in which the threaded beta-CDs are self-aggregated into a typical channel-type crystal structure after water incubation. At the same time, they converse into a beta-CD dispersed state in which the entrapped beta-CDs are randomly dispersed along the backbone after DMF treatment. Herein the effects of solvent variations on the residing states of beta-CDs on the polymeric backbone in a selected PR sample were investigated in detail. Treating the sample using solvents, such as water, THF, chloroform, methanol, ethanol, acetone, methylene dichloride, anhydrous ether and n-hexane, produces the beta-CD aggregated state PRs. Meanwhile, treatments using DMF, DMSO and NaOH aqueous solution yield the beta-CD dispersed state PRs. The self-aggregated structures of beta-CDs threaded onto the Pluronic F127 chain were evidenced by using XRD,C-13 CP/MAS NMR and FTIR techniques. Additionally, the mechanism for the solvent effects on the residing states of beta-CDs in the PR sample was discussed. These findings would not only contribute to a comprehensive understanding of the self-aggregated structure of CD-based PRs, but also promote to exploit solvent-responsive PRs as smart materials. (C) 2011 Elsevier Ltd. All rights reserved.