Hair aging comprises weathering of hair shaft and aging of hair follicles. The latter mainly manifests as the decrease in melanocyte function or graying of hair, androgenetic alopecia and senescent alopecia. The scalp is also subject to intrinsic (physical aging) or external factors (such as smoking, ultraviolet irradiation, et al). Experimental evidence supports the hypothesis that oxidative stress plays an important role in skin and hair aging. At present, treatment options for androgenetic alopecia include topical minoxidil tincture, oral finasteridc, and autologous hair transplantation. If the hair graying is inreversible, hair colorant is the main choice for the masking of hair color change.