PROBLEM TO BE SOLVED: To provide a composition, a stabilizer and a stabilization method that improve the stability of astaxanthin compounds which are known to have useful effects, such as skin-whitening ability and aging prevention.SOLUTION: There is provided a composition containing: a component (A) that is an astaxanthin compound； and a component (B) that is a plant of a scientific name of Alpinia galanga (Zingiberaceae), or its extract. There is provided a stabilizer for astaxanthin compounds, the stabilizer containing a plant of a scientific name of Alpinia galanga (Zingiberaceae), or its extract, as an active ingredient.【課題】美白・老化防止等の有用な効果を有することが知られているアスタキサンチン類の安定性を高める組成物、及び安定化剤や安定化方法を提供すること。【解決手段】成分（Ａ）アスタキサンチン類、並びに、成分（Ｂ）ショウガ科ハナミョウガ属ナンキョウ植物又はその抽出物を含有する組成物；ショウガ科ハナミョウガ属ナンキョウ植物又はその抽出物を有効成分とするアスタキサンチン類の安定化剤。【選択図】なし
