PROBLEM TO BE SOLVED: To provide, by finding a novel substance to be able to efficiently proliferate a stem cell while maintaining its undifferentiated state, the substance as an agent for maintaining undifferentiated state of a stem cell or an agent for promoting its proliferation, and further to provide a wound healing agent which has skin wound healing action, is capable of being easily used in a skin regenerative medical field and a beautification field, and is high in safety and inexpensive.SOLUTION: Provided is an agent for maintaining undifferentiated state of a stem cell or an agent for promoting its proliferation or a wound-healing agent, each of which comprises as an active ingredient, mixture of one or plural kinds of fatty acid glyceride represented by general formula (I): wherein at least one of R, Rand Rrepresents an acyl group having 16-22 carbon atoms and derived from an unsaturated fatty acid； and the rest represents an acyl group derived from a saturated fatty acid or a hydrogen atom.SELECTED DRAWING: None【課題】幹細胞を、未分化状態を維持させたまま、効率良く増殖させることができる新たな物質を見出し、幹細胞の未分化状態維持剤若しくは増殖促進剤として提供すること。また、皮膚の創傷治癒作用を有し、皮膚再生医療又は美容分野で簡便に利用でき、しかも安全性が高く、安価な創傷治癒剤を提供すること。【解決手段】下記の一般式（Ｉ）:【化１】（式中、Ｒ1、Ｒ2、Ｒ3のうちの少なくとも１個は炭素数１６～２２の不飽和脂肪酸由来のアシル基を示し、残りは飽和脂肪酸由来のアシル基又は水素原子を示す。）で表わされる脂肪酸グリセリドの１種又は２種以上の混合物を有効成分として含有する、幹細胞の未分化状態維持剤若しくは増殖促進剤、又は創傷治癒剤。【選択図】なし
