PROBLEM TO BE SOLVED: To provide a composition in which decreased dispersibility of a given modified peptide is suppressed when pH is less than 7.0.SOLUTION: The invention relates to a modified peptide comprising one or more kinds of side groups having a unit selected from structures represented by the following formulae (Ia)-(Ic) and salts of such structures, and a liquid composition containing a long chain alkyl trimethyl quaternary ammonium salt or N-long chain alkyl pyridinium salt, wherein (a total compounding amount of the long chain alkyl trimethyl quaternary ammonium salt and N-long chain alkyl pyridinium salt)/(a compounding amount of the modified peptide) is 0.5 or more, and pH is less than 7.0. The formula (Ia) is -S-S-(CH)-COOH (where, n is 1 or 2). The formula (Ib) is -S-S-CH(CH)-COOH. The formula (Ic) is -S-S-CH(COOH)-CH-COOH.【課題】ｐＨが７．０未満であるときに、所定の変性ペプチドの分散性低下が抑えられた組成物の提供。【解決手段】下記式（Ｉａ）～（Ｉｃ）で表される構造及びこれらの構造の塩から選ばれた単位を有する側鎖基を一種又は二種以上備える変性ペプチド、及び、長鎖アルキルトリメチル４級アンモニウム塩又はＮ－長鎖アルキルピリジニウム塩が配合され、（長鎖アルキルトリメチル４級アンモニウム塩及びＮ－長鎖アルキルピリジニウム塩の総配合量）／（変性ペプチドの配合量）が０．５以上、ｐＨが７．０未満である液状組成物。－Ｓ－Ｓ－（ＣＨ２）ｎ－ＣＯＯＨ （Ｉａ）（式（Ｉａ）中、ｎは１又は２である。）－Ｓ－Ｓ－ＣＨ（ＣＨ３）－ＣＯＯＨ （Ｉｂ）－Ｓ－Ｓ－ＣＨ（ＣＯＯＨ）－ＣＨ２－ＣＯＯＨ （Ｉｃ）【選択図】図１
