The Yushan National Park area can be further divided into five geologic terranes based on its geological characteristics. According to a preliminary survey, the Dongpu-Yushan area includes three geologic terranes: non-metamorphic sedimentary rock terrane from the Miocene epoch, Yushan terrane of metamorphic slate complex from the Palaeocene epoch, and the Lushan terrane of sub-metamorphic slate complex from the Miocene epoch. The first stage of this research project was still mainly a geological survey of the study area. Aerial photographs of the entire study area were also taken. The identification and analysis results obtained from the photographs were used to produce a preliminary line graph of the Dongpu-Yushan area, which was further used to produce an aerial geological graph based on related field geological data. An in-depth field survey was conducted in order as a followup and to make comparisions of formations and line structures in the key study area. 20 sites with geological significance along the main trails and forest roads were selected in the Dongpu-Yushan area and geological information were established at these sites according to the plan developed in this survey.