Novel lipid peptide and hydrogel

There is provided a lipid peptide that is capable of forming a hydrogel with an extremely small amount thereof over a liquid property range from acidic to alkaline, and a hydrogel having high environmental suitability, biocompatibility and biodegradability. A lipid peptide represented by Formula (1): (where R 1 represents an aliphatic group having 9 to 23 carbon atoms; R 2 , R 3 , R 4 and R 5 independently represent a hydrogen atom, an alkyl group having 1 to 7 carbon atom(s) which optionally has a branched chain having 1 to 3 carbon atom(s), a phenylmethyl group, a phenylethyl group or a -(CH 2 ) n -X group, and at least one of R 2 , R 3 , R 4 and R 5 represents a -(CH 2 ) n -X group; n represents the number of 1 to 4; X represents an amino group, a guanidino group, a -CONH 2 group or a 5-membered ring, a 6-membered ring or a fused heterocyclic ring composed of a 5-membered ring and a 6-membered ring which optionally have 1 to 3 nitrogen atom(s); and m represents 1 or 2), and a hydrogel comprising the lipid peptide.