PROBLEM TO BE SOLVED: To provide a water-soluble composition which can solubilize black ginger constituents specifically into water at a higher concentration as compared with conventional techniques.SOLUTION: The above object is solved by the water-soluble composition containing black ginger (Kaempferia parviflora), &gamma cyclodextrin, and branched cyclodextrin, wherein the amount of 5,7-dimethoxyflavone is 0.3 wt.% or more, and the mass ratio (&gamma cyclodextrin: branched cyclodextrin) of the &gamma cyclodextrin and the branched cyclodextrin is 1:0.01-6.