The effects of water on the liquid crystalline structure of the copolymer poly(11-(4＇cyanobiphenyloxy)undecyl acrylate-co-acrylic acid)s (poly(11CBA-co-AA)s) were investigated. When the molar fraction of 11CBA, F, was higher than 0.26, the copolymers did not dissolve but swelled in water to give the hydrogels, keeping the smectic A ordering. This smectic A phase of the copolymers off = 0.37 and 0.29 transferred to more organized smectic I ordering by further incorporation of water, while the SmA ordering of the copolymer of F = 0.26 disappeared to give the amorphous state. The role of water and the mechanism for forming a liquid crystalline structure in the hydrogel have been discussed.