Objective: To investigate the effects of hesperidine on B16 and HaCat cell lines irradiated by Narrowband-UVB light. Methods: MTT, NaOH assay, Takahashi technique were applied to measure the proliferation of B16 and HaCaT cells, the synthesis of melanin, and the tyrosinase activity of B16 cell respectively. The expression of CXC receptor 2 (CXCR2) on keratinocytes was analyzed by flow cytometry. To detect the contents of transforming growth factor-β1 (TGF-β1), enzyme linked immunosorbent assay was applied. Results: The findings indicated that hesperidine at the concentrations of 50-600 mg/L did not affect the proliferation of B16 and HaCaT cells. At the doses of 200 mg/L and over, hesperidine inhibited the tyrosinase activity and melanogenesis in B16 cells. The levels of TGF-β 1 in the supernatant of cultured keratinocytes presented as "wave shape" according to hesperidine contents. The expression of CXCR2 in the normal cultured keratinocytes did not change with different concentrations of hesperidine. However, the expression of CXCR2 in the cultured cells irradiated by narrowband-UVB light was increased obviously. When 200-600 mg/L hesperidine were added to the media, in which the cultured keatinocytes would be irradiated by Narrowband-UVB light later, the expression of CXCR2 decreased markedly in a dose-dependent manner, especially, when the dosage of hesperidine was 600 mg/L. Conclusions: Hesperidine has various biological effects, with gentle effectiveness, and without cytotoxicity. It is a potent plant extract for whitening and photoprotection.