An extract of Asplenium nidus L. includes pyropheophorbide a methyl ester (C34H36N4O3), pheophorbide a methyl ester (C35H36N4O5), 1-linleoyl-3-linolenoyl-glycerol (C39H66O5), 1-linleoyl-2,3-dipalmitoyl-rac-glycerol (C53H98O6) and 1,3-dipalmitoyl-sn-glycerol (C35H68O5). The extract of Asplenium nidus L. is obtained by using a method including steps of: solvent extraction, using an solvent to extract an Asplenium nidus L. sample and to obtain an extract, with a w/v ratio between the solvent and the Asplenium nidus L. sample being 50-60 mg/ml; and column chromatography, fractionating the extract with water and ethanol as eluent to obtain several fractions including fraction a to fraction i, and further evaporating and lyophilizing fraction b, c, d or their combination to obtain an extract of Asplenium nidus L.