This study was conducted to investigate the native Phytolacca insularis in Ulleung Island for their distribution and ecological characteristics. P. insularis, called as "Sum-Ja-Ri-Gong", is very rare plant which is only restricted in Ulleung Island. It is a plant out of 217 endangered plant species designated by the Korea Forest Service (1996). The native sites were discovered several plants in the small communities at the area from 32m to 116m above the sea level in the seashore of Ulleung Island. The average vegetation height of herb layer in the native sites was 0.77m and average coverage percentage of vegetation layer was 75.56%. Average 11.89 species were emerged on a plot. P. insularis has a tendency to emerged with Galium spurium var. echinospermon and Artemisia lavandulaefolia community.