A newly designed anthracene derivative having gluconamides at its peripheral branches formed a photo-responsive hydrogel. SEM observation of the xerogel showed a network structure consisting of fibrils. Upon photoirradiation (lambda >300 nm) of the hydrogel, regioselective photodimerization of the anthracene moiety occurred to give head-to-tail photodimers and the physical state changed from the gel to the sol.