The present invention is related to a composition, comprising at least an algae fluorescent protein treated with a protease to become peptides. The algae fluorescent peptides absorb ultraviolet rays having wavelengths less than 498 nm, and emit red and yellow lights having wavelengths between 570-700 nm to obtain the effect of photodynamic therapy.本發明係關於一種用於美容的組合物,包含至少一胜肽化海藻螢光蛋白。該胜肽化海藻螢光蛋白可吸收小於498 nm的紫外光,並放出570-700 nm的黃紅光,以達到光動力療法的效果。