This research was conducted over a time span of three years, from 2009 to 2011. Twenty-one surveys in total, seven times per year, were done between April and June of each year on major trees on trails around Donghaksa and Gapsa in Mt. Gyeryong National Park in order to identify foodplants of the Lepidoptera larvae and their characteristic appearances. During the survey of Lepidoptera larvae in trees along trails around Donghaksa and Gapsa, 377 individuals and 21 species in 8 families were identified. The 21 species were Alcis angulifera, Cosmia affinis, Libythea celtis, Adoxophyes orana, Amphipyra monolitha, Acrodontis fumosa, Xylena formosa, Ptycholoma lecheana circumclusana, Choristoneura adumbratana, Archips capsigeranus, Pandemis cinnamomeana, Rhopobota latipennis, Apochima juglansiaria, Cifuna locuples, Lymantria dispar, Eilema deplana, Rhodinia fugax, Acronicta rumicis, Amphipyra erebina, Favonius saphirinus, and Dravira ulupi. Twenty-one Lepidoptera insect species were identified in 21 species of trees, including Zelkova serrata. Among them, A. angulifera, C. affinis, and L. celtis were found to have the widest range of foodplants. Additionally, it was found that many species of Lepidoptera insects can utilize more species as foodplants according to the chemical substances in the plants and environments in addition to the foodplants noted in the literature. Also, it is thought that more species can be identified with a survey of various woody and herbaceous plants.