To provide a parakeratosis inhibitor, pore reducing agent and skin roughness preventing/ameliorating agent that exhibit capabilities of parakeratosis inhibition, pore reduction, skin roughness prevention/amelioration, etc., and further provide a skin preparation for external use having these capabilities. There are provide a parakeratosis inhibitor and a pore reducing agent each comprising at least one compound selected from the group consisting of a glycine derivative, an aminodicarboxylic acid derivative, an acylaminodicarboxylic acid derivative, a pyrrolidinecarboxylic acid derivative, a piperidinecarboxylic acid derivative, a hexamethyleneiminecarboxylic acid, a beta-alanine derivative and salts of these derivatives. Further, there are provided a parakeratosis inhibitor, a pore reducing agent and a skin roughness preventing/ameliorating agent each comprising at least one compound selected from the group consisting of specified glycine derivatives and salts thereof and specified aminosulfuric acid derivatives and salts thereof. Still further, there are provided skin preparations for external use comprising these compounds.本發明係關於提供一種具有不全角化症抑制、毛孔縮小、皮膚粗糙防止‧改善等之功能之不全角化症抑制劑、毛孔縮小劑、皮膚粗糙防止‧改善劑，更提供一種具有前述功能之皮膚外用組成物。本發明係提供一種不全角化症抑制劑、毛孔縮小劑，其特徵為1種或2種以上選自甘胺酸衍生物、胺基二羧酸衍生物、醯基胺基二羧酸衍生物、吡咯烷羧酸衍生物、哌啶羧酸衍生物、六伸甲基亞胺羧酸衍生物、β-丙胺酸衍生物、及該各衍生物的鹽所成群之化合物所成者。又，提供一種含有1種或2種以上選自特定甘胺酸衍生物及其鹽、與特定胺基硫酸衍生物及其鹽所成群之化合物的皮膚外用組成物。
