The present invention provides a skin penetration-accelerating composition that eliminates the need for forming a drug into a particle structure and dramatically improves the skin penetration properties of a drug without breaking the skin tissue. The present invention also provides a preparation for transdermal administration containing the skin penetration-accelerating composition and a patch preparation containing the skin penetration-accelerating composition. The present invention provides a skin penetration-accelerating composition containing a flavonoid compound and used for accelerating skin penetration of a drug.