A skin whitening composition includes amorphigeni or a salt thereof as an effective ingredient. Amorphigeni suppresses the expression of tyrosinase and induces autophagy on melanosomes. As such, it was confirmed that amorphigeni not only suppresses melanin production but also exhibits the effect of removing melanin previously produced by α-MSH (melanocyte-stimulating hormone). Accordingly, amorphigeni can be advantageously used as a functional material for skin whitening and skin lightening.