Hydrogels are generally thought to be formed by nano-to micrometre-scale fibres or polymer chains,either physically branched or entangled with each other to trap water.Although there are also anisotropic hydrogels with apparently ordered structures,they are essentially polymer fibre/discrete polymer chains-based network without exception.Here we present a type of polymer-free anisotropic lamellar hydrogels composed of 100-nm-thick water layers sandwiched by two bilayer membranes of a self-assembled nonionic surfactant,hexadecylglyceryl maleate.