The present invention relates to a composition for preventing hair loss and, more specifically, to a compound having a structure in which Minoxidil and a peptide are chemically connected, and to a pharmaceutical composition or cosmetic composition for preventing hair loss or promoting hair growth comprising the compound. The compound having a structure in which Minoxidil and a peptide are chemically connected according to the present invention has not only excellent physiological activity such as hair loss reduction, hair growth promotion or cell growth promotion, but also excellent stability in water, and can therefore be useful as a composition for preventing hair loss and promoting hair growth.