We prepared a gel starting from deacetylated chitin nanofibers by utilizing electrostatic interactions with an anionic cyclodextrin, sulfobutyl ether beta-cyclodextrin (SBE-beta-CyD). Among the various CyDs tested and their derivatives, SBE-beta-CyD formed a stiff, nonfluid elastic gel that can be easily formed into a variety of shapes, whereas other gels prepared from neutral CyDs formed a weak, rather fluid gel. The viscosity of the deacetylated chitin nanofiber/SBE-beta-CyD gel was higher by about one order of magnitude at a 1.0 w/v % concentration of SBE-beta-CyD. Both the elastic (G') and viscous (G '') moduli of the deacetylated chitin-nanofiber gel increased in the presence of SBE-beta-CyD, and the G' values were much higher than the G '' values. The SBE-beta-CyD functioned to reinforce the deacetylated chitin nanofiber gel, by anchoring the fibers into a three-dimensional network through electrostatic interactions.