The present invention provides a hydrogel-forming material, a premix and a hydrogel-forming method capable of forming a hydrogel by a simpler method and under a milder temperature condition (room temperature). A dispersed phase (A) comprising a lipid peptide-type compound comprising at least one of the compound represented by the following formula (1) or a pharmaceutically usable salt thereof, water, and a fatty acid salt. And a hydrogel-forming material comprising a water-soluble acidic polymer dispersed phase (B). (In the formula, R 1 represents an aliphatic group having 9 to 23 carbon atoms, R 2 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a branched chain having 1 or 2 carbon atoms. , R3 represents a-(CH2) n-X group, n represents a number of 1 to 4, and X represents an amino group, a guanidino group, a -CONH2 group, or a 5-membered ring having 1 to 3 nitrogen atoms Or a condensed heterocyclic ring composed of a 6-membered ring or a 5-membered ring and a 6-membered ring.) [Selection] None【課題】より簡便な方法にて、且つより温和な温度条件（室温）にて、ヒドロゲル形成が可能なヒドロゲル形成材料、プレミックス並びにヒドロゲルの形成方法を提供する。【解決手段】下記式（１）で表される化合物又はその薬学的に使用可能な塩のうちの少なくとも一種からなる脂質ペプチド型化合物と、水と、脂肪酸塩とを含有する分散相（Ａ）と、水溶性の酸性高分子の分散相（Ｂ）とからなる、ヒドロゲル形成材料。（式中、Ｒ１は炭素原子数９乃至２３の脂肪族基を表し、Ｒ２は水素原子、又は炭素原子数１若しくは２の分枝鎖を有し得る炭素原子数１乃至４のアルキル基を表し、Ｒ３は－（ＣＨ２）ｎ－Ｘ基を表し、ｎは１乃至４の数を表し、Ｘはアミノ基、グアニジノ基、－ＣＯＮＨ２基、又は窒素原子を１乃至３個有し得る５員環若しくは６員環又は５員環と６員環から構成される縮合複素環を表す。）【選択図】なし
