There is provided a hydrogel-forming material in which a hydrogel can be formed in preparation of the hydrogel even after a process of stirring a gelator in a medium with heating to dissolve and disperse the gelator, and cooling the mixture to room temperature with stirring, and a hydrogel material in which a gel can be reformed by standing at room temperature even after a hydrogel obtained using the material is converted into a sol by shaking. A hydrogel-forming material comprising a lipid peptide gelator consisting of a compound of Formula (1) or a pharmaceutically usable salt thereof: (wherein, R 1 is a C 9-23 aliphatic group, R 2 is a hydrogen atom or a C 1-4 alkyl group optionally having a C 1-2 branched chain, R 3 is a -(CH 2 ) n -X group, n is a number of 1 to 4, and X is an amino group, a guanidino group, a -CONH 2 group, a 5-membered ring optionally having 1 to 3 nitrogen atom(s), a 6-membered ring optionally having 1 to 3 nitrogen atom(s), or a fused heterocycle composed of a 5-memberd ring and a 6-membered ring optionally having 1 to 3 nitrogen atom(s)), water, and a fatty acid salt as an additive.
