In this paper, we studied the optical properties of LEDs that inhibit Malassezia sympodialis and activate HFDPC(Human follicle dermal papilla cells) to prevent dandruff and hair loss. The optical data of the test results confirmed measurement traceability by calculating the horizontal irradiance irradiated directly to the cells. In the test results, when irradiated with light of 393 ± 3nm, it was found to be effective in improving antifungal performance when increasing the horizontal irradiance while lowering the energy density in the effective energy range where the light absorption of M.sympodialis is easy. In the scalp cell activation test, light was irradiated to HFDPC at an energy density of 5 ± 0.17J/㎠ with the 630 ± 1nm LED and the energy density of 20 ± 1.22J/㎠ with the 850 ± 1nm LED. As a result, the incidence rates of IGF-1 and VEGF, which are hair growth promoting factors, were increased by 38% and 44%, respectively, compared to the normal group not irradiated with light. In particular, when the 850 ± 1nm LED is irradiated, the Incidence of the inflammatory factor(COX-2, MMP-2) is not changed compared to the normal group.