The present invention relates to a skin-whitening and skin-protection composition that comprises stilbenoid (s) and/or stilbenoid-containing extract (s) obtained from Dendrobium plants, such as Dendrobium officinale and Dendrobium nobile for the management of melanogenesis, skin-darkening and skin-aging. More particularly, the present invention further relates to the usage of Dendrobium ingredients and stilbenoids to reduce the formation of melanin in melanocytes. The present invention further relates to the usage of Dendrobium ingredients and stilbenoids to reduce the generation of reactive oxygen species and oxidative free radicals. The use of Dendrobium-derived extracts or ingredients or stilbenoids in the formulation of skin-protection, skin-whitening and/or anti-skin aging products. Compounds for use in preparation of a composition for treating, preventing, and/or delaying the progress of skin darkening or for use in skin-whitening and skin-protection which are synthesized from dihydro-resveratrol and the related synthesis method are also provided.