Abstract: A nanoparticle composition is provided for preventing hair loss and promoting hair growth. It is based on herbal materials and thus has no harmful side effects on the body. When applied to the scalp, the nanoparticle composition deeply infiltrates into the dermis to promote blood circulation therein and provide nutrients thereto. Accordingly, the nanoparticle composition stimulates and activates hair follicles to thus promote the metabolism of hairs. Also, the nanoparticle composition exerts antioxidant activity on the scalp to thus inhibit depilation and aid in hair regrowth.