PROBLEM TO BE SOLVED: To provide a nail care agent having excellent biodegradability and safety.SOLUTION: There is provided a nail care agent composed of a polylactic acid-containing aqueous dispersion, wherein the polylactic acid satisfies at least one of the following physical properties (A) to (E): (A) 80 to 100 mol% of the total monomer molecules constituting the polylactic acid is a lactic acid monomer； (B) the molar ratio (L-lactic acid/D-lactic acid) between L-lactic acid and D-lactic acid constituting the polylactic acid is 1 to 7； (C) the reduced viscosity is 0.3 to 1.5 dl/g； (D) the number average molecular weight is 10000 to 90000 and (E) the Tg is 20 to 54°C.SELECTED DRAWING: None【課題】生分解性及び安全性に優れたネイルケア剤の提供。【解決手段】ポリ乳酸含有水系分散体から成るネイルケア剤で、ポリ乳酸が下記の物性（Ａ）～（Ｅ）の少なくとも１つを満たす、ネイルケア剤：（Ａ）ポリ乳酸を構成する総モノマー分子の８０～１００モル％が乳酸モノマーである；（Ｂ）ポリ乳酸を構成するＬ－乳酸とＤ－乳酸とのモル比（Ｌ－乳酸／Ｄ－乳酸）が１～７である；（Ｃ）還元粘度が０．３～１．５ｄｌ／ｇである；（Ｄ）数平均分子量が１０，０００～９０，０００である；（Ｅ）Ｔｇが２０～５４℃である。【選択図】なし
